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[Display omitted] • Novel Mn-FeS 2 /MWCNT heterogeneous Fenton catalyst were synthesized. • Mn-FeS 2 /MWCNT showed excellent performance in actual wastewater treatment. • The co-enhancement effect of Mn doping and combination of MWCNT was clarified. • Mn doping into FeS 2 promoted the generation of superoxide radical. • The Fe-S-C and Mn-S-Fe bond improved stability and reactivity of catalyst. Recently, pyrite (FeS 2) has been discovered as a promising heterogeneous Fenton catalyst due to the excellent generation of Fe(II). However, the limited inherent catalytic efficiency and poor stability hinder its wide application in wastewater treatment. Herein, a novel carbon nanotube-loaded Mn-doped FeS 2 (Mn-FeS 2 /MWCNT) catalyst was synthesized for high radical production and durable Fenton catalysis. The optimized Mn-FeS 2 /MWCNT exhibited 100 % of bisphenol A elimination within 15 min, which was ∼174- and ∼20-fold than that of FeS 2 and FeS 2 /MWCNT, respectively, and Mn-FeS 2 /MWCNT demonstrated remarkable stability after five cycles (less than 0.8 mg/L Fe leaching in each cycle). The generation of hydroxyl radicals (OH) and superoxide radicals (O 2 −) was enhanced with Mn doping and the introduction of MWCNTs. Mechanistic studies and DFT calculations revealed that Mn doping tuned the electron density between Fe and Mn in the Fe–S–Mn linkage, further improving the H 2 O 2 absorption energy on the Mn-FeS 2 surface for radical generation. Introducing MWCNTs improved the reactivity and stability of the catalyst by electron transfer of the Fe–S–C bond. This work determined the co-enhancement effect of metal sulfur links and sulfur carbon bonds on pyrite-based materials and provides a promising catalyst for wastewater remediation. [ABSTRACT FROM AUTHOR]

[Display omitted] Vanadia-based catalysts are widely used in selective catalytic reduction (SCR) reaction for reducing nitrogen oxides emissions, however, they only exhibit sufficient DeNO x efficiency within a narrow temperature window. In this study, a catalyst embedded with electrothermal alloy was prepared. The catalyst surface temperature could be heated using the electrothermal alloy, in order to widen the operating temperature window of the V 2 O 5 -WO 3 /TiO 2 catalyst. Experimental results revealed that the electrothermal alloy embedded V 2 O 5 -WO 3 /TiO 2 catalyst can maintain superior NH 3 -SCR performance and high resistance to H 2 O in a wide gas temperature range of 100–400 °C by controlling the surface temperature. In the meantime, the NH 4 HSO 4 poisoned catalyst could be efficiently regenerated through electric heating, and NO x conversion can be restored to the level of fresh samples. Additionally, the effect of additives including methylcellulose and glass fiber, on the physicochemical properties of the plate-type catalyst was also investigated, and the catalyst samples were characterized by means of BET, XRD, NH 3 -TPD, H 2 -TPR, TG and SEM-EDS. This study proves the electric heating strategy is a promising way to enhance the performance of the V 2 O 5 -WO 3 /TiO 2 during wide temperature SCR applications. [ABSTRACT FROM AUTHOR]

Copper is a mono-metallic catalyst to produce large amounts of hydrocarbons during the CO 2 electrochemical reduction reaction (CO 2 RR). Nevertheless, the high overpotential of the reaction process and the low selectivity of currently known catalysts for multi-carbon (or single) products still prevent this process from approaching commercialization. Here, we report the synthesis of different ratios of Cu/Co catalysts with multiple active centers treated with H 2 cold plasma. The resultant Cu 2 Co 1 catalyst showed a high current density of 20.7 mA cm−2 and a Faraday efficiency of 70 % for C 2 H 4. This Cu–Co bimetallic multi active center structure is conducive to the generation of *CO and further coupling to form C2 products, thereby improving the selectivity of C 2 H 4. This study provides a new way to design multi-active center tandem catalysts for the efficient production of C 2 H 4 products. [Display omitted] • The synergistic effect of Cu0, Co0 and Cu2+ affected the adsorption activation of CO 2 molecules during the CO 2 RR process. • The Cu 2 Co 1 electrocatalyst yields C 2 H 4 as major products with a FE of 70 % at −1.0 V vs. RHE and excellent durability (200 h). • This work represents a new method for design and preparation of Cu–Co multi-active centers tandem catalysts to enhance the C 2 H 4 FE in CO 2 RR. [ABSTRACT FROM AUTHOR]

[Display omitted] • Thermal pretreatment favors organically modified M to enhance its hydrophobicity. • Organic modifier with short carbon chain facilitates the formation of Mn4+. • MnCe-M 8 -600 with abundant Mn4+ and Ce3+ increases NO X conversion. • The hydrophobicity of MnCe-M 8 -600 weakens the interaction between –OH and catalyst. The H 2 O resistance of low-temperature NH 3 -SCR catalysts is a key factor for practical applications. This work aims to strategically enhance the hydrophobicity of catalysts by intercalating surfactants into montmorillonite (M) via its cation exchange capacity. Various thermal pretreatment temperatures and chain lengths of surfactants have been used to enhance the hydrophobicity and interlayer spacing of montmorillonite, respectively. As a result, MnCe-M 8 -600 (with thermal pretreatment at 600 °C and the chain length of surfactant = 8) exhibits good low-temperature NH 3 -SCR performance and H 2 O resistance due to its labile oxygen, hydrophobicity, and structural stability. It is worth noting that the hydrophobicity of MnCe-M 8 -600 weakens the interaction between –OH and the catalyst, thereby continuously maintaining the redox ability and transferring electrons between Mn4+ and Ce3+. The results of the H 2 O resistance test showed that the NO X conversion of MnCe-M 8 -600 decreased by only 6% in the presence of 10% H 2 O, and its activity was fully recovered after turning off H 2 O. Hence, MnCe-M 8 -600 shows high activity and H 2 O resistance and is a promising catalyst for low-temperature NH 3 -SCR system applications. [ABSTRACT FROM AUTHOR]

The graphical abstract was designed to characterize the viewpoint that our manuscript wanted to convey. The pristine idea comes from the "four great classical Chinese novels". The three animals, Monkey King (red), Ba Jie (yellow), and Sha Monk (blue), help Tang Monk (the man in the middle) take the scriptures home and become the Buddha. The picture corresponded with the standpoint that the different strategies for achieving the goals of (i) increasing the number of HER active sites; (ii) reducing the ΔG H* ; (iii) enhancing the electrical conductivity, thus synergistically enhancing the catalytic properties of carbon-based materials. Compared with graphical abstracts in other reviews (pie chart with method classification), we believe that the artistic graphical abstract can impress readers more. [Display omitted] • Increasing the number of HER active sites by interface/defect engineering approaches. • Reducing the ΔG H* can enhance the HER performance. • Tuning the d-band centers of transition metals is benefit for accelerating HER kinetic. • Future research directions about carbon-based catalysts in MECs were given. Developing sustainable hydrogen production by efficient conversion technologies is vital to address environmental and energy challenges. Microbial electrolysis cells (MECs) can produce hydrogen from wastewater and solid wastes, which is considered a promising technology. The design and fabrication of cathodic catalysts for the hydrogen evolution reaction (HER) is a key factor in the future development of MECs. Carbon materials have the advantages of large specific surface area, high electrical conductivity, good stability, and low price. However, the catalytic activity of pristine carbon materials is usually low. Previous reviews mainly focused on the classification of different catalyst materials, but little about mechanisms. This review comprehensively addresses the mechanism related to enhancing HER performance and the regulation of the characteristics of composites based on non-noble metals and carbon materials via different interfacial/defect engineering methods for achieving the ultimate goals: (i) increasing the number of HER active sites; (ii) reducing the Gibbs free-energy of hydrogen binding (ΔG H*); (iii) enhancing the electrical conductivity. It is noteworthy that when the electrochemical desorption, i.e., the Heyrovsky step or Tafel step, is the rate-determining step of HER, adjusting the d-band center of the transition metal site to optimize the hydrogen adsorption energy may further enhance catalytic activity. In addition, the effects of cathodic biofilms on HER performance are discussed. Finally, we present several potential perspectives for boosting HER to promote the application of MECs. [ABSTRACT FROM AUTHOR]

[Display omitted] • Porous NiBi alloy provides active sites for adsorbing of N 2. • The synergistic effect of Ni and NiBi enhance the NRR performance of NiBi alloys. • Ni 91.5 Bi 8.5 shows a high ammonia yield at a low overpotential of −0.3 V. Electrochemical nitrogen reduction reaction (NRR) in ambient condition provides a sustainable avenue for large-scale NH 3 production. However, the development of effective and durable NRR catalysts to promote NH 3 synthesis rate and Faraday efficiency (FE) remains a challenge due to the inertness of the N≡N bond. Herein, porous NiBi catalysts which provides abunant active sites were prepared by chemical dealloying of the precursor. Combining theoretical calculations and experimental verification, it is demonstrated that the synergistic effect of Ni and NiBi facilitates the adsorption of N 2 , inhibits the competition reaction, and reduces the free energy of intermediates (*NNH). Porous Ni 91.5 Bi 8.5 exhibits high catalytic activity for NH 3 formation with a yield of 18.35 μg h−1 mg−1 and a FE of 51.12% at −0.3 V vs. RHE, outperforming most reported NRR electrocatalysts under ambient conditions. This strategy is an effective and universal technique for synthesizing catalysts that shows great potential in energy conversion applications. [ABSTRACT FROM AUTHOR]

Cobalt-based catalysts have been widely explored in the degradation of organic pollutants based on peroxymonosulfate (PMS) activation. Herein, we report an MXene nano-Co 3 O 4 co-catalyst enriched with oxygen vacancies (O v) and steadily fixed in nickel foam (NF) plates, which is used as an efficient and stable PMS activator for the removal of 1,4-dioxane (1,4-D). Ti originating from MXene was doped into the Co 3 O 4 crystal, generating large amounts of O v , which could provide more active sites to enhance PMS activation and facilitate the transformation of Co2+ and Co3+, causing a high stability. As a result, the 1,4-D removal efficiency of the NF/MXene-Co 3 O 4 /PMS system (k app : 2.41 min−1) was about four times higher than that of the NF/Co 3 O 4 /PMS system (k app : 0.62 min−1). In addition, singlet oxygen was the predominant reactive oxygen species. Notably, the 1,4-D removal of the NF/MXene-Co 3 O 4 /PMS system was over 95% after 20 h operation in the single-pass filtration mode with only 3.72% accumulative Co leaching, showing excellent stability and reusability of NF/MXene-Co 3 O 4. This work provides a defect engineering strategy to design a robust and stable catalytic system for water treatment, which expands the application of MXene in the field of environmental remediation. [Display omitted] • MXene nano-Co 3 O 4 co-catalyst generates large amounts of O v. • NF/MXene-Co 3 O 4 /PMS system exhibits an excellent 1,4-D removal rate (k app : 2.41 min−1). • Singlet oxygen was the major ROS for 1,4-D removal. • NF/MXene-Co 3 O 4 have both outstanding stability and reusability. [ABSTRACT FROM AUTHOR]

Moisture curing of polysilazane coatings at room temperature is of advantage to industrial applications, though it often takes a longer time than the other curing methods. To tackle this problem, tetrabutylammonium chloride (TBAC) is applied in this work as an efficient catalyst for the hydrolysis and condensation reactions of polymethyl(hydro)/polydimethylsilazane coatings under ambient conditions. In the suggested catalytic mechanism, the Si–H group is nucleophilically attacked by chloride ions to form a transient Si–Cl group, which is then nucleophilically substituted by a hydroxyl group from the moisture environment. It is found that by adding TBAC in the polysilazane coating, 1.6 times more of the reactive groups (Si–H, Si–NH) are consumed during the curing process in a shorter time (the dry-to-touch time for the uncatalyzed and the TBAC-catalyzed polysilazane coatings are ca. 19 h and 1 h, respectively), while 2 times more of the Si–O–Si groups are formed. Owing to the significantly enhanced crosslinking rate and degree, the coating quality and the mechanical properties are greatly improved. The hardness and the elastic modulus of the coating are increased by a factor of two and four, respectively. [Display omitted] • Moisture curing of polysilazane at room temperature is highly accelerated by tetrabutylammonium chloride. • Hydrolysis of the Si–H groups is catalyzed by chloride ions. • The surface morphology of the polysilazane coating is significantly improved. • The hardness and the E modulus of the catalyzed-coating are increased by a factor of two and four, respectively. [ABSTRACT FROM AUTHOR]

Due to highly heterogeneity of pyrolyzed transition metal-nitrogen-carbon (M-N-C) catalyst, elucidating mechanisms of roles of metal in enhancing oxygen reduction reaction (ORR) is challenging. Here, we design a surface structurally-defined precursor with Fe-N coordination to atomically disperse iron (Fe) on N-doped carbon hollow microspheres surface (NHMs@Fe) by pyrolysis of the precursor. The obtained NHMs@Fe catalyst exhibits a high ORR activity comparable to commercial Pt/C catalyst. The detailed analyses confirmed that (i) Fe atoms are uniformly distributed on N-poor carbon surface, and (ii) the designed Fe-N x coordination are destroyed and don't convert into Fe-N x active sites after thermal activation. We find that single Fe atoms produced by carbothermal reduction are directly trapped into adjacent carbon vacancies generated by the removal of N to create active sites for ORR. This work not only reveals the origin of activity of Fe-N-C catalyst but also opens an avenue for preparation of high-performance M-N-C catalysts. [Display omitted] • Fe atoms are uniformly dispersed on the N-doped carbon by pyrolysis of structure defined precursor. • The obtained NHMs@Fe catalyst exhibits a high ORR activity comparable to commercial Pt/C catalyst. • The designed Fe-N x coordination are destroyed and don't convert into Fe-N x sites after pyrolysis. • Single Fe atom is directly trapped into adjacent N-removed vacancy to create active site for ORR. • Low coordination single Fe atoms anchored on carbon vacancies are responsible for high ORR activity. [ABSTRACT FROM AUTHOR]

Solar-induced overall water splitting to produce hydrogen is inspiring towards energy sustainability, but it is also formidable due to its limited efficiency seriously hindering its scale up for practical application. CdS is an important transition metal sulfide with low-work-function. However, its photostability is often deteriorated due to photocorrosion influence. To overcome this issue, single-atom Pd was employed here to decorate CdS to form a CdS-Pd nanocatalyst through a simple and controllable photoinduced reduction strategy. The synergetic semiconductor (CdS)-metal (Pd) interaction promotes the fast bulk-to-surface electron migration, thereby the resultant CdS-Pd (3.83‰) nanocatalyst shows considerable structural stability and dramatically improved solar-induced HER activity in overall water splitting, about 110-fold higher than that of pristine CdS. Meanwhile, high apparent quantum yields (AQYs) of 4.47%/1.81% and 33.92%/27.49% were respectively achieved with this decorated nanocatalyst under the light of 420 nm/500 nm in absence and presence of scavenger, demonstrating the high-efficiency under broadband light illumination. Density functional theory (DFT) calculation supports that the easy formation of H* intermediates on the decorated nanocatalyst due to low energy barriers accounts for the internal promoted mechanism for hydrogen production. This study provides important insight to gain stable CdS-based photocatalysts for high-efficient hydrogen production by overall water splitting. Fast bulk-to-surface electron migration for overall water splitting under simulated solar light. [Display omitted] • Single-atom Pd was decorated to CdS through a simple and controllable strategy. • Synergetic semiconductor (CdS)-metal (Pd) interaction promotes fast bulk-to-surface electron migration. • High apparent quantum yields were achieved with this decorated nanocatalyst. • Hydrogen production on the decorated nanocatalyst presents low energy barriers. [ABSTRACT FROM AUTHOR]

Low thermal stability and metal sintering are considered the reasons for the deactivation of three-way catalysts, especially on transition metals. Herein, using a versatile clay halloysite nanotubes (Hal) as a support and two surfactants, cetyltrimethylammonium bromide (CTAB) and polyvinylpyrrolidone (PVP), modified Hal with hydrophobic external surfaces and Pd-PVP colloids with various particle sizes were synthesized by adjusting the ratios of surfactants. As a result, modified Hal could make CuO nanoparticles coordinate with unsaturated Al in the internal lumen of Hal, which is favored to increase the CuO nanoparticle dispersion and inhibit their migration. In particular, Cu@HC-2 (Hal/CTAB weight ratio = 2) exhibited a higher n(Cu)/n(Al) ratio, surface active oxygen species and CuO species, which endowed better catalytic performance. The T 50 of CO conversion decreased from 250 °C (unmodified Cu/Hal catalyst) to 180 °C. However, the NO x reduction is less effective due to the limited reducibility of transition metal. The reduced Pd-PVP nanoparticles with the molar ratio of PVP/Pd = 4 were immobilized on the Cu-based catalyst, which contributes to the smaller Pd0 nanoparticles and the maximum NO x conversion. Unexpectedly, excessive PVP-Pd may block the gas reaction with CuO species and weaken the CO and C 3 H 8 oxidation. [Display omitted] • The hydrophobic outer surface of Hal was formed by CTAB modification. • CuO NPs were embedded into the lumen of Hal to inhibit metal sintering. • The coordination of Cu Al gives rise to smaller CuO NPs with good dispersion. • The NO x conversion was improved by Pd0-PVP, which was anchored on Cu@HC-2. [ABSTRACT FROM AUTHOR]

Construction of 3D porous g-C 3 N 4 /GO-M (Au, Pd, Pt) composite catalysts with enhanced cocatalyst-support interaction and promoted electron transfer for HER. • 3D porous g-C 3 N 4 /GO-M (Au, Pd, Pt) composite catalysts were constructed. • Bonding interaction enhances the structure stability of the 3D porous skeleton. • Enhanced cocatalyst-support interaction promotes the electron transfer of the catalyst. • The prominent HER activity (136-fold greater of 3D p-CNG skeleton) is achieved on the optimal catalyst. • The excellent durability and reproducibility were presented by this optimal catalyst. Photocatalytic hydrogen production is regarded as an ideal strategy to solve energy issues. Graphene phase carbon nitrogen compound (g-C 3 N 4) is commonly used to prepare improved photocatalysts due to its typical structural advantages. However, it generally presents low photostability of functional cocatalysts (e.g. precious metals) for simple 2D-layered structure of 2D g-C 3 N 4. Herein, graphene oxide (GO) is applied to construct 3D porous g-C 3 N 4 /GO (p-CNG) skeleton via a thermal treatment aiding by template technique. Then, precious-metal (Au, Pd, Pt) cocatalysts were respectively immobilized to the 3D p-CNG skeleton to construct the 3D p-CNG-M (Au, Pd, Pt) composite catalysts. The typical 3D porous structure and bonding interaction between g-C 3 N 4 and GO increase the specific surface area and improve the anchoring stability of cocatalysts. Meanwhile, precious-metal cocatalysts acted as the electron acceptors remarkably increase the active sites and promote the electron-hole separation. Thereby, the resultant 3D p-CNG-M composite catalysts present remarkably enhanced hydrogen evolution reaction (HER) activities under simulated solar light (SSL), and the optimal 3D p-CNG-Pt composite catalyst possesses the prominent HER activity (2565.81 μmol g−1 h−1) at pH = 10.5 for the stronger cocatalyst-support interaction, which is about 136-fold greater of 3D p-CNG skeleton (18.93 μmol g−1 h−1). Furthermore, its AQY is about 21.6 % under illumination (λ =420 nm). Especially, the excellent durability and reproducibility were achieved during long time photoinduction and multi-recycling. This study provides a potential strategy for enhancing the photostability and improving the SSL-induced HER performance of precious-metal modified photocatalyst. [ABSTRACT FROM AUTHOR]

Bimetallic Ni–Fe phosphide electrocatalysts were in-situ synthesized through direct phosphorization of metal salts on carbon cloth (CC). The Fe dopant remarkably enhances the OER performance of Ni 2 P in alkaline medium through the electronic structure modulation of Ni. The (Fe 0.5 Ni 0.5) 2 P/CC electrode, composed of uniform films coated on carbon fibers, delivers a low overpotential of 260 mV with a small Tafel slope of 45 mV·dec−1 at the current density of 100 mA cm−2, outperforming most reported non-noble electrocatalysts and commercial RuO 2 electrocatalyst. The (Fe 0.5 Ni 0.5) 2 P/CC also displays superior electrochemical stability at high current density. An appropriate Fe dopant level facilitates the in-situ transformation of Ni–Fe phosphides into active NiFeOOH during alkaline OER. This work simplifies the synthesis procedure of metal phosphides. [Display omitted] • Bimetallic Ni–Fe phosphide electrocatalysts are in-situ synthesized on carbon cloth. • Exceptional OER performances are showed by the Ni–Fe phosphide electrocatalysts. • Insight into the mechanisms underlying the excellent OER activities. • Synthetic strategy can be extended into other metal phosphides. [ABSTRACT FROM AUTHOR]

With the growing attention on both environmental and energy issues, the catalytic conversion of CO 2 has gained tremendous interest of researchers. Herein, we report a bimetal CoZn-ZIF derived highly efficient catalyst CoZn-Z for CO 2 methanation. After prereduction before the catalytic test, an inverse ZnO/Co structure with plentiful uniformly dispersed active sites could be formed, and the obtained CoZn-Z catalyst showed high Co dispersion with principally exposed Co (0002) lattice plane. Sufficient active sites, increased basicity and CO adsorption resulted in enhanced CO 2 methanation catalytic activity, and CO 2 conversion of 62.9 %, CH 4 selectivity of 99.2 % with a STY CH4 of 0.21 mol CH4 ·g cat. −1·h−1 were achieved at 300 °C, 2.6 times of monometallic Co-Z and exceeding most of the reported Co-based catalysts. Furthermore, based on in situ FTIR and DFT calculation, the formation of diverse reaction intermediates was studied and different dominant reaction pathways have been proposed for CoZn-Z and Co-Z. This investigation exhibited great potential of MOFs derived catalysts as superior CO 2 methanation catalysts and elucidates the promoting effect of ZnO in Co-based CO 2 methanation catalysts for the first time. [Display omitted] • CoZn-Z catalyst with ZnO/Co reverse structure and plentiful uniformly dispersed active sites was derived from CoZn-ZIF. • CoZn-Z showed a STY CH4 of 0.21 mol CH4 ·g cat. −1·h−1 at 300 °C, 2.6 times that of its monometallic counterpart. • The promoting effect and reaction pathway on ZnO promoted Co-based methanation catalyst were studied for the first time. • ZnO boosted methanation catalytic activity by improving the metal-dispersion, alkalinity and CO adsorption strength. • The introduction of ZnO changed the dominant reaction path of CO 2 methanation over Co-based catalyst. [ABSTRACT FROM AUTHOR]

Hybrid catalysts composed of transition metals and nitrogen-doped carbons have been emerging as one of efficient electrocatalysts for electrochemical CO 2 -to-CO under ambient conditions. Herein, NiO loaded on mesoporous graphene with tunable concentration of pyridinic nitrogen is rationally synthesized by using low-intensity pulsed laser irradiation and pyrolysis treatments. Comprehensive experiments verify that, it is pyridinic N, rather than pyrrolic N, when bonded to Ni, that significantly enhance the electrochemical CO 2 reduction reaction performance. The optimized catalyst exhibits a high CO Faradaic efficiency of 87.5% at a low potential of −0.74 V vs. reversible hydrogen electrode, associated with negligible attenuation of continuous operation over 12 h. [Display omitted] • Low-intensity pulsed laser irradiation is used to adjust the types of N dopants. • Pyridinic-N-Ni could significantly enhance the CO 2 RR performance. • Pyridinic-N-Ni could accelerate the CO 2 RR kinetics and greatly inhibit the HER process. [ABSTRACT FROM AUTHOR]

• Ordered mesoporous supports endow good dispersion of Ag nanoparticles. • Ag/SiO 2 catalysts show remarkable support effects on both activity and selectivity. • Supports effects originate from distinct activation and diffusion behaviors. • Competitive-adsorption of H 2 versus DMO dominates DMO semi-hydrogenation. Support materials play vital roles in heterogenous catalysis via the so-called support effects, and understanding on the support effects is beneficial for the design of high-performance catalysts. Herein, we represent detailed investigations on the support effects of Ag catalysts for dimethyl glycolate (DMO) semi-hydrogenation to methyl glycolate (MG), where G6 silica with amorphous mesopores, SBA-15 with parallel mesopores and silica nanospheres (MSNS) with center-radial ones were employed as the supports. The hydrogenation activity decreases in the order of Ag/MSNS > Ag/SBA-15 > Ag/G6 while the MG selectivity in the order of Ag/G6 > Ag/MSNS > Ag/SBA-15 at the same reaction conditions, indicating remarkable support effects on both activity and selectivity. Structural characterizations, temperature programmed experiments and in-situ FTIR of DMO adsorption experiments demonstrate that the weak confinement effect of G6 leads to the larger sized Ag nanoparticles and weakened activation of DMO and H 2 , which contributes to low hydrogenation activity. In contrast, the ordered mesoporous SBA-15 and MSNS deliver well confinement effects for Ag nanoparticles and the activation of DMO and H 2 , but the distinct pore structures result in different activation and diffusion behaviors. Finally, DMO conversion and MG yield are well correlated with the competitive adsorption of H 2 versus DMO on Ag catalysts, indicating such competitivity as a descriptor for DMO semi-hydrogenation over Ag catalysts. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • N-doped sulfonated acid-base bifunctional catalyst was synthesized. • Appropriate acid/base ratio favored 5-HMF production with a yield of 50.04%. • Medium basicity and pyridinic N content affected 5-HMF yield and selectivity. • DFT calculation reveled pyridinic N significantly reduced reaction energy barrier. • Glucose isomerization proceeded by pyridinic N-triggered proton transfer mechanism. Considering the essential role of acidic/basic sites in efficient 5-hydroxymentylfurfural (5-HMF) production from cellulose, the superiority of acid-base bifunctional catalysts was unfolded. However, the lack of in-depth research on catalytic mechanism of active sites, especially the basic sites, greatly hinders its chemical utilization. Herein, N-doped sulfonated bifunctional catalysts were rationally designed. The synthesized NCS-1H catalyst exhibited outstanding activity and recyclability. Favorable 5-HMF yield of 50.0 % with 62.9 % of selectivity was obtained. Spin polarized density function theory (DFT) analysis revealed a pyridinic N-triggered proton-shift mechanism of glucose isomerization. Catalyzed by pyridinic N, the proton of glucose on C2 was shifted to O5, leading to the cleavage of C1-O1 bond. As a result, an enol intermediate was formed and converted to fructose. Compared to pyrrolic N and graphitic N, pyridinic N significantly reduced the reaction energy barrier of rate-determining step to 0.79 eV, i.e., C1-O1 bond cleavage. [ABSTRACT FROM AUTHOR]

A novel and high-efficiency Pd/TM x O y -rGO/CFP (TM x O y = Co 3 O 4 , Mn 3 O 4 , Ni(OH) 2) electrocatalyst for directly integrated membrane electrode was synthesized by controllable cyclic voltammetry electrodeposition combined with hydrothermal process. The results showed excellent performance towards methanol oxidation reduction. The Pd/Co 3 O 4 -rGO/CFP as-prepared catalyst has the best electrocatalytic activity, and mass activity is 5181 mA·mg−1 Pd , which is about 40 times and 4.3 times that of the commercial Pd/C and Pt/C catalyst (JM). It can be attributed that the small size of Pd nanoparticle, uniformity of distribution, and the synergistic interaction between transition metal oxide on the support surface and Pd nanoparticles. The prepared Pd/TM x O y -rGO/CFP composite electrode is a promising catalyst for integrated membrane electrode assembly of proton exchange membrane fuel cells in the future. The as-prepared Pd/TM x O y -rGO/CFP composite electrode by cyclic voltammetry electrodeposition is a promising catalyst for integrated membrane electrode assembly of proton exchange membrane fuel cells in the future. [Display omitted] • Integrated electrode is synthesized via cyclic voltammetry electrodeposition on CFP. • Uniform distributed and small-sized Pd nanoparticles are controllably electrodeposited. • The support-metal synergistic interaction is utilized. • The catalytic activity of as-prepared catalyst is about 40 times that of Pd/C (JM). [ABSTRACT FROM AUTHOR]

K 0.5 Na 0.5 NbO 3 (KNN) particles were prepared by a solid–state method. X–ray diffraction, scanning electron microscopy, UV–visible spectrophotometry, and electrochemical impedance spectroscopy were used to study the structure, morphology, and properties of the samples. The obtained KNN is a ferroelectric material with orthorhombic perovskite structure at room temperature. The KNN particles can be used as piezo/photo–bicatalysts for degrading organic pollutants by utilizing vibrational and solar energy; the catalytic activity of the particles can be significantly improved owing to their polarization under an applied electric field. Poled KNN particles show a bicatalytic degradation ratio of rhodamine B (RhB) dye reaching 92% after 60 min. The results indicate that the KNN particles can be applied as attractive ferroelectric catalysts for organic pollutant degradation. [Display omitted] [ABSTRACT FROM AUTHOR]

Transition metal-based compounds, due to their excellent ORR catalytic performance under alkaline condition, have recently emerged as one of the most promising alternatives to noble metal-based ORR catalysts. It is worth noting that manganese oxide can take an unique advantage for decomposition of intermediate adsorption products H 2 O 2 and can effectively reduce O 2 to OH−. However, most research has focused on MnO 2 , while attention has rarely been paid to MnO catalysts. In addition, under high-temperature pyrolysis condition, MnO is the most stable manganese oxide but MnO nanoparticles easily agglomerate. Hence, it is very difficult to obtain well-dispersed and small-sized MnO nanoparticles. Herein, on the basis of pre-synthesizing uniformly distributed manganese complexes on the reduced graphene oxide (rGO), we innovatively prepare highly dispersed and small-sized MnO nanoparticles (~3.94 nm) via high-temperature pyrolysis, which are uniformly anchored on N-doped reduced graphene oxide (NrGO) as an efficient oxygen reduction electrocatalyst. The as-obtained MnO/NrGO (1050 °C) electrocatalyst achieves satisfactory onset potential (0.942 V) and half-wave potential (0.820 V) under alkaline condition. And the limiting current density is 4.17 mA cm−2, which is very close to that of Pt/C (20 wt%, JM). Meanwhile, MnO/NrGO (1050 °C) catalyst presents superior longstanding durability and methanol resistance than Pt/C (JM). This work indicates that high-temperature pyrolysis can improve the purity of manganese oxide, simultaneously the defects of NrGO can reduce particle size of MnO nanoparticles, which are greatly beneficial to improve ORR performance. This work provides a new idea for research of MnO catalysts for ORR in the future. Novel electrocatalysts, comprising highly dispersed MnO nanoparticles on N-rGO, were prepared by high-temperature pyrolysis and displayed excellent activity and stability for ORR in alkaline solution. [Display omitted] • The Mn complex was uniformly distributed on rGO by hydrothermal method. • The small-sized MnO particles (~3.94 nm) were well dispersed on NrGO by pyrolysis. • Manganese oxides transform into pure MnO with the increasing pyrolysis temperature. • The ORR performance of as-prepared catalyst is very close to that of Pt/C (JM). [ABSTRACT FROM AUTHOR]

[Display omitted] • CrPO 4 @Co 3 O 4 was synthesized and used to activated PMS for phenacetin degradation. • CrPO 4 @Co 3 O 4 exhibited a superb catalysis and over 98% phenacetin was degraded by PMS within 15 min. • Rate constant of PNT degradation mediated by CrPO 4 @Co 3 O 4 was 8 times as high as that by Co 3 O 4. • High performance of catalyst resulted from high BET surface area and synergy of CrPO 4 and Co 3 O 4. • SO 4 •− together with 1O 2 was main reactive oxygen species responsible for the PNT degradation. In this study, CrPO 4 -supported Co 3 O 4 (CrPO 4 @Co 3 O 4) as an efficient peroxymonosulfate (PMS) catalyst was obtained for the first time and used to eliminate phenacetin (PNT) from aqueous solution efficiently. CrPO 4 @Co 3 O 4 composite exhibited a superb catalytic performance, and over 98% PNT was degraded by PMS (0.5 mM) within 15 min, which is much more efficient than in the systems of CrPO 4 /PMS and Co 3 O 4 /PMS. The excellent catalytic performance of CrPO 4 @Co 3 O 4 was attributed to its higher BET surface area. On the other hand, the presence of PO 4 3- in the catalyst might improve the conversion of Co(III) to Co(II). The latter served as the main active site for the PMS activation. CrPO 4 @Co 3 O 4 also possessed superior stability and reusability, and the removal rates of PNT remained over 91% through 4 cycle tests. Solution pH significantly impacted the PNT decomposition, and the optimal catalytic degradation of PNT was achieved in an initial range of 5 to 7. Humic acid, HCO 3 −, and Cl− inhibited PNT degradation. Radical scavenging experiments and EPR technology revealed that SO 4 •− free radicals were the main reactive oxygen species (ROS) responsible for PNT degradation. While O 2 •− mainly acted as the intermediate to form SO 4 •− and 1O 2. To assess the practical application of the CrPO 4 @Co 3 O 4 /PMS system, the PNT degradation was investigated in real lake water. Based on HPLC-TOF-MS2 analysis, 14 intermediates were identified, and the degradation pathways were further inferred. Therefore, this study provides a feasible strategy for the valuable use of CrPO 4 as recycled material and a practical solution for the efficient degradation of organic contaminants. [ABSTRACT FROM AUTHOR]

It had remained a challenge to rationally design a highly efficient bifunctional catalyst for overall water splitting using non-precious metals. Herein, a simple method was presented to synthesize a self-supported catalyst using nickel foam (NF) filled with nanoscale Co 3 O 4 (Co 3 O 4 /NF) as a hierarchical porous support. A NiCoP alloy was deposited on the Co 3 O 4 /NF in the form of profiling growth by electroless plating (NiCoP@Co 3 O 4 /NF). And then, the NiCoP@Co 3 O 4 /NF electrodes were phosphorylated. The profile-grown NiCoP alloy transformed into a two-dimensional (2D) flake-like Co-doped Ni x P y , forming a self-supported electrocatalyst (Co-Ni x P y @Co 3 O 4 /NF). The Co-Ni x P y @Co 3 O 4 /NF electrode exhibited a large surface area, excellent conductivity, and synergy between metal atoms. This electrode also possessed low overpotentials of 72 and 120 mV to drive the hydrogen and oxygen evolution reactions at 10 mA cm−2. For overall water splitting, the self-supported Co-Ni x P y @Co 3 O 4 /NF electrode only required a low voltage of 1.47 V to reach the current densities of 20 mA cm−2 in 1 M KOH with long-term stability for 36 h. This work represented an achievement the exploration of a new bifunctional of transition metal phosphides with high performances in water splitting. [Display omitted] • A reasonable space division strategy of NF increased the specific surface area. • Two-dimensional flake-like Co-doped Ni x P y immobilized on the surface of Co 3 O 4 /NF. • The Co-Ni x P y @Co 3 O 4 /NF catalyst exhibited excellent HER and OER performance. • The Co-Ni x P y @Co 3 O 4 /NF electrode possessed a hierarchical porous structure. [ABSTRACT FROM AUTHOR]

The development of green and efficient heterogeneous catalysts for permanganate (Mn(VII)) activation remains unexplored. Given the different roles of crystal structures of MnO 2 in many applications, it is of great significance to investigate the reactivity of MnO 2 with different phases for Mn(VII) activation. In this study, it was found that the first-order rate constants for phenol degradation in the presence of 100 μM Mn(VII) follow an order of α-MnO 2 (0.0884 min−1) > δ-MnO 2 (0.0746 min−1) > β-MnO 2 (0.0417 min−1) > γ-MnO 2 (0.0396 min−1). The fact is in line with Mn(VII) adsorption, which can be related closely to the surface area, pore diameter, and isoelectric points of the catalysts. Other phenolic contaminants such as parachlorophenol and bisphenol A were also degraded efficiently by the Mn(VII)/α-MnO 2 system. After coordination with surface Mn species in MnO 2 , the Mn–O bond of Mn(VII) is stretched with an increase in electron transfer reactivity and a decrease in oxygen atom transfer ability. A surface-promoted electron transfer process is then proposed for phenol degradation by the system. A good adaptability and reusability of the Mn(VII)/α-MnO 2 system were observed. The influence of several parameters and comparisons with other catalysts were also studied. This work provides insights into the phase-dependent reactivity of MnO 2 catalysts for Mn(VII) activation and pollutant degradation. [Display omitted] • MnO 2 structures affected Mn(VII) adsorption and phenol degradation. • The high surface areas, pore diameters, and isoelectric points were important. • The OAT reactivity of adsorped Mn(VII) decreased and ET reactivity increased. • Direct ET mechanism played a significant role in phenol degradation. • The MnO 2 catalyst showed good reusability during successive runs. [ABSTRACT FROM AUTHOR]

[Display omitted] • As the green electrolyte, DES-CH 3 CN solution with excellent electrochemical window. • Ni-Co metal and oxide supported on C promote C α –C β and C β –O cleavage efficiently. • C α -OH support β-C elimination to result in C α –C β cleavage. In this study, C α –C β and C β –O bond cleavage of β-O-4 model compound (2-phenoxy-1-phenylethanol) were accomplished by electrocatalysis depolymerization process in deep eutectic solvents (DES) systems. We have investigated the application of Ni-Co/C catalysts on working electrode, which were synthesized with impregnation method. The Ni-Co/C with porous structure and abundant active sites, was shown an excellent electrocatalysis activity. Specific structure of Ni-Co/C could provide greatly efficient adsorption and desorption capacity to promote C α –C β and C β –O bond cleavage. Therefore, in this electrocatalysis depolymerization process, the highest depolymerization rate exceeded 90%. And the yields (and conversion rates) of products (including benzaldehyde, acetophenone, benzoic acid, phenol) can reach to 124.08 mg/g (25.05%), 23.29 mg/g (4.15%), 44.64 mg/g (7.83%), 30.3 mg/g (6.9%). Furthermore, the electrocatalysis mechanism of C α –C β and C β –O bond was investigated. The cleavage of C α –C β and C β –O bond was initiated by in situ generated free radicals through Ni-Co/C. Then, the cleavage of C α –C β and C β –O bond were occurred by ·OH and ·O 2 −. The results were showed that the C α –C β bond cleavage was more in line with the β-C elimination and free radical pathways, and C β –O bond cleavage was consistent with direct oxidative addition. The enhanced electrocatalytic efficiency of the low-cost Ni-Co/C electrocatalyst combined with its good chemical stability and selectivity, which offer a promising route for developing an efficient lignin depolymerization technology. [ABSTRACT FROM AUTHOR]

[Display omitted] • MnO x /AC composite catalyst was prepared by a novel redox precipitation strategy. • MnO x /AC-0.3 showed remarkable low-temperature activities for toluene combustion. • Oxygen vacancies were efficiently constructed via strong metal-support interaction. • Coupling adsorption oxidation capacity plays a key role in toluene combustion. Activated carbon (AC) has been widely used as adsorbent and support of noble metal catalysts for the elimination of VOCs, owing to its high specific surface area and effective regulation of interfacial properties of catalysts via metal-support interaction. Herein, a series of MnO x /AC composite catalysts are prepared by in-situ redox precipitation method using KMnO 4 as manganese source, ethylene glycol (EG) as reducing agent and coconut shell-based AC as active carrier. The obtained MnO x /AC catalysts have been fully characterized by XRD, SEM, TEM, N 2 adsorption-desorption, FT-IR, XPS, EPR, H 2 -TPR, TPD-MS and toluene-TPSR-Ms (with and without O 2) and their catalytic properties are evaluated for low temperature oxidation of toluene. It is found that the introduction of AC support significantly enhanced the adsorption capacity of toluene upon the MnO x /AC composite catalysts. Amongst, the MnO x /AC-0.3 shows excellent low-temperature catalytic activity (T 90 = 193 °C), which can be related to highly efficient synergy of AC and MnO x species in toluene combustion. Especially, the construction of efficient MnO x /AC interfaces with more oxygen vacancy active sites, better lattice oxygen mobility, and stronger molecular oxygen activation ability, makes MnO x /AC-0.3 composite catalyst possess the best coupling adsorption oxidation capacity of toluene, and thus resulting in significant improvement in catalytic performance. Additionally, the obtained MnO x /AC-0.3 catalyst has also exhibited good catalytic stability and water resistance (5 vol%). This work deepens the understanding of the metal-support interaction in MnO x /AC composite catalysts and provides new ideas for the design of environmentally friendly catalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • Effect of the local coordination environment on the HER and ORR activities of Pd 1 -N x C y was studied by DFT calculations. • Stability in terms of Pd formation energy was highly dependent on the local coordination environment. • Changing the local coordination number and coordinated components can significantly impact the adsorption energies of intermediates. • Promising HER and ORR electrocatalysts were designed through varying the local coordination environment. Development of more efficient HER and ORR electrocatalysts is crucial for the production and utilization of H 2 as a clean and sustainable energy carrier. M−N−Cs based single-metal-atom electrocatalysts have been extensively reported to be the alternatives to cost-ineffective Pt electrocatalysts, and their activities were significantly sensitive to the local coordination environment, but the underlying mechanism is still unclear yet. Herein, effects of the local coordination numbers and coordinated components of a single Pd atom in Pd 1 -N x C y on the HER and ORR activities were systematically investigated using theoretical calculations. We found that change in the local coordination environment is an effective way to modulate the electrochemical activities, and the four-atom-coordinated Pd 1 -N 2 C 2 -2 and the three-atom-coordinated Pd 1 -N 3 C 0 -3 were the most promising HER and ORR electrocatalysts, respectively. This work provides valuable insights into designing more efficient M−N−Cs electrocatalysts for HER and ORR, as well as the other important electrochemical processes. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ternary catalysts of Cu nanoparticles encapsulated in FeNi-MOF are prepared by one-step method. • The ternary interface of Cu-Feδ+-Ni2+ with three-atom dual-active sites shows a positive synergy. • The Cu@FeNi-MOF catalyst shows high catalytic activity and stability for NH 3 BH 3 hydrolysis. • A catalytic mechanism at ternary interface is proposed. The development of high-performance and low-cost catalysts through a simple method remains a major challenge for the hydrogen generation from hydrogen-storage materials. In this work, we developed a strategy of embedding copper nanoparticles in iron-nickel metal–organic framework (MOF) via a one-step solvothermal process to form a ternary interface of copper-iron-nickel with a favorable local cooperative environment and electronic structure. The optimized Cu@FeNi-MOF catalyst exhibits outstanding stability and excellent catalytic activity with a turnover frequency of 132.4 min−1 in the hydrolysis of ammonia borane, surpassing all reported catalysts containing Cu, Fe or Ni and comparable with noble metal catalysts. Based on the experiments and density functional theory (DFT) calculations, the unprecedented activity originates from the three-atom dual-active sites of Cu-Feδ+-Ni2+ interfaces (namely Cu0 and O-Ni2+). Feδ+ significantly promotes the catalytic activity of Cu0 and O-Ni2+ sites through the ternary interfaces. This study opens up a novel approach to effectively improve the performance of non-precious metals by fabricating ternary interfaces with a synergistic effect. [ABSTRACT FROM AUTHOR]

[Display omitted] • MSNS with center-radial mesopores shows shorter pore length than SBA-15. • Shorter pore length enhances performance of Ag/MSNS catalyst for DMO hydrogenation. • Differently sized MSNS with distinct pore lengths are fabricated for Ag catalyst. • Relationship between performance and diffusion is established for Ag/MSNS catalyst. Precisely regulating mesopore structures toward enhanced diffusion of reactants and targeted product is of great significance for achieving simultaneously improved activity and selectivity, which is exemplified by this work employing mesoporous silica with distinct structured mesopores as support for Ag catalysts to selectively hydrogenate dimethyl oxalate (DMO) into methyl glycolate (MG). Mesoporous silica nanosphere (MSNS) with center-radial pores shows shorter pore length than SBA-15 with parallel mesopores, which is beneficial for the diffusion process and thus gives rise to enhanced hydrogenation activity. Inspired by these insights, MSNSs sized in 50, 90, 120 and 160 nm are further synthesized to regulate pore length and systematically explore their effects on the reaction. The diffusion process is enhanced with decreasing the size of MSNS from 160 to 50 nm, as elucidated by the effective diffusion time constant (D e /R2) determined by zero-length column (ZLC) method. Accordingly, DMO can facilely diffuse into the mesopores with shorter length to access the active sites while the formed MG product can easily diffuse out to avoid the over-hydrogenation process, which is corroborated by the comparison for performances of these Ag/MSNSs catalysts. Notably, a moderately short pore length, balancing well the diffusion and hydrogenation process, is more preferable for achieving both higher activity and better selectivity to MG, and MSNS sized in 90 nm supported Ag catalyst thus exhibits the greatest performances, with MG selectivity up to 96.6 % at 99.7 % of DMO conversion. [ABSTRACT FROM AUTHOR]

• There graphene-based transition metal coordination polymers have been evaluated as the energetic catalysts in Al-based composites. • These catalysts are well doped in the PVDF/AP matrix as the oxidizer shell of Al-based composites prepared by a spray drying method. • The high energy level but low burn rate has been achieved for the Al@PVDF/AP in presence of these graphene-based catalysts. In this paper, energetic combustion catalysts doped core–shell Al@PVDF/AP composites have been fabricated via a spray-drying method, where three kinds of graphene-based energetic coordination polymers (GECPs, GO-CHZ-Co, GO-CHZ-Ni and GO-CHZ-Cu) are employed. These composites have been characterized comprehensively in terms of morphologies, thermal decomposition behaviors, energy density, combustion performances and condensed combustion products (CCPs). The results show that the GO-CHZ-Co and GO-CHZ-Cu could increases the heat of explosion for Al@PVDF/AP composites from 6885.2 J·g−1 to 7491.0 J·g−1 and 7390.1 J·g−1, respectively, which are 8.8 % and 7.3 % higher than the blank reference samples. Moreover, the burn rates for these composites decrease when GO-CHZ-Co or GO-CHZ-Ni is included, indicating that these composites are promising candidates with improved energy density even unusually with decreased burn rates. [ABSTRACT FROM AUTHOR]

The essential active sites and intermediates over TiO x -based catalysts for the whole NH 3 -SCR reaction were ascertained. [Display omitted] • The oxygen could promote NO x adsorbing as monodentate and bidentate nitrates. • The DRIFTS bands of 1604 cm−1 represented the coordinated NH 3 species at the Cu2+. • NH 3 -SCR at 200 °C mainly followed Eley-Rideal (E-R) pathway over CuNbTiO x. • The reaction routes transformed from E-R into Langmuir-Hinshelwood (L-H) with temperature increasing. NH 3 -SCR has been an efficient technology for purifying NO x from industrial facilities. However, it is still a huge challenge to clearly understand the intrinsic mechanisms. Here, in situ DRIFTS was employed for elucidating the adsorption behaviors, active sites and reaction routes over the model catalyst of CuNbTiO x. The oxygen played a vital role in the reactant adsorption and reaction process, especially for NO x adsorbing, in which oxygen could promote monodentate and bidentate nitrates forming and bridged nitrate increasing. Then the correlation between DRIFTS peak locations and active sites for NH 3 adsorption was further defined, thereinto, the bands at ca. 1604 cm−1 represented the coordinated NH 3 species at Cu2+. Similar with most SCR catalysts, CuNbTiO x exhibited various catalytic activities among different temperature ranges. It was found that NH 3 -SCR reaction occurred mainly via Langmuir-Hinshelwood pathway at 200 °C, in which the relatively inert nitrates and NH 3 adsorption species restricted the low temperature activity. Afterwards, the reaction mechanism transformed into Eley-Rideal when the temperature was elevating to a high temperature of 400 °C due to the weak adsorption of NO x. These new findings provide an innovative view for understanding the surface reaction on catalysts, further facilitate the development of NH 3 -SCR catalysts. [ABSTRACT FROM AUTHOR]

• Electrochemical-induced switch toward C=O bond in Pd-catalyzed CAL hydrogenation. • The COL selectivity is up to 90% in neutral pH with considerable faraday efficiency. • The self-standing Pd cathode outperforms other catalysts for CAL hydrogenation. • Large π-conjugated system is decisive to C=O selectivity. • Organic solvent retards total hydrogenation of semi-hydrogenated products. It is particularly challengeable to achieve C=O selectivity for Pd catalysts in thermal catalytic hydrogenation of cinnamaldehyde (CAL). This work offers a new electrochemical strategy that enables an unexpected switch toward C=O bond for CAL hydrogenation, based on the specific interaction between CAL and electrolyte-modulated Pd surface. Under galvanostatic electrolysis, guanosine 5′-monophosphate-modulated Pd electrode affords a record cinnamyl alcohol (COL) selectivity of 90.3% in neutral catholyte with no sacrifice of CAL conversion, showing the faradaic efficiency of 68.2%. It is of great interest to find that the aromatic moiety of CAL determines the preferential activation toward C=O bond over Pd surface under electric field. It is reported for the first time that selective hydrogenation of α, β-unsaturated aldehydes can be altered by electrochemical environment located between Pd electrode and surrounding electrolyte involving alkali cation along with organic solvent. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • 0.1%WO 3 /CeO 2 (f) with flower-like morphology exhibited a wonderful NH 3 -SCR performance. • W loading strengthened the acidity while the structure of CeO 2 optimized the reducibility. • A strong interaction existed between surface WO x species and CeO 2 support. • NH 3 oxidization/deformation species could react with the gaseous or adsorbed NO x. • Bridged nitrates participated in the reaction via a L-H route over 0.1%WO 3 /CeO 2 (f). A novel flower-like 0.1%WO 3 /CeO 2 (f) catalyst with high-efficiency was fabricated for the selective reduction of NO x by NH 3. In contrast to traditional WO 3 /CeO 2 , this catalyst exhibited a significant SCR performance of 90% NO x conversion and 95% N 2 selectivity within a wide temperature range of 175–450 °C and great H 2 O and/or SO 2 resistance under a high GHSV of 177,000 h−1. A variety of analytical techniques including SEM, XRD, XPS, NH 3 -TPD, H 2 -TPR and in situ DRIFTS-MS were employed for the catalysts characterization to fully understand the reaction mechanism over WO 3 /CeO 2 catalysts. It was found that the flower-like structure promoted a more uniform dispersion of tungsten species on the support and a stronger interaction between WO 3 and CeO 2 , thereby increasing the acid sites and surface vacancies. Moreover, more chemical active oxygen and trivalent cerium species were presented on 0.1% WO 3 /CeO 2 (f). In situ DRIFTS-MS and H 2 -TPR revealed that the reducibility was optimized for 0.1% WO 3 /CeO 2 (f). Then NH 3 oxidation species could react with gaseous or adsorbed NO x during Eley-Rideal (E-R) pathway for 0.1%WO 3 /CeO 2 (f) at a high temperature (300 °C). Meanwhile, NO x was reduced into more active bridged nitrates participating in the reaction via Langmuir-Hinshelwood (L-H) route, contributing to its superior deNO x performance. In comparison, the formation of inert adsorbed NH 3 oxidization/deformation species and bridged nitrates suppressed the SCR reaction over 0.1%WO 3 /CeO 2 , resulting in its inferior deNO x activity. This study not only provides a new strategy for developing high-efficiency ceria supported NH 3 -SCR catalyst, but also lays a foundation for investigating the reaction mechanism of cerium-based catalyst for further practical applications. [ABSTRACT FROM AUTHOR]

Excavating highly efficient M-N-C electrocatalysts for electrochemical CO 2 reduction (ECR) is of paramount importance. Herein, we report a single-atom Co-N-C catalyst (CoN 4 -CB) with a high CO Faradaic efficiency (FE CO , 98.7%) in ECR comparable to that of a similarly prepared NiN 4 -CB catalyst. Impressively, CoN 4 -CB demonstrates a CO turnover frequency of 27173 h−1 and a CO current density of −33.6 mA∙cm−2 at −0.76 V, 20.2 and 6.8 times higher than that of NiN 4 -CB, respectively. In a solar-driven ECR system composed of a Si solar cell and a flow cell, CoN 4 -CB shows a remarkably large current density of 98.3 mA∙cm−2 with an average FE CO of 92.1%. Theoretical calculations suggest that the energy barrier for *COOH formation largely decreases on CoN 4 sites compared with NiN 4 sites, leading to a low onset potential and high activity for CO production. This work will boost the development of efficient M-N-C electrocatalysts and further practical application of solar-driven ECR system. [Display omitted] • CoN 4 -CB catalyst enables efficient ECR to CO. • CoN 4 -CB displays comparable selectivity to NiN 4 -CB but much enhanced activity. • An optimized solar driven system for ECR to CO at high current density. • DFT results well supported the experimental results. [ABSTRACT FROM AUTHOR]

The development of low-cost and easily accessible catalysts to realize the practical applications of catalytic combustion of volatile organic compounds remains a challenge. In this work, a series of Fe–Mn oxides catalysts were prepared via a facile redox-precipitation route for the elimination of o-xylene. Among the synthesized catalysts, Fe3Mn1-RP exhibited excellent activity for o-xylene elimination with a T 50 and T 90 of 223 °C and 236 °C, respectively (o-xylene concentration = 500 ppm, WHSV = 36,000 mL g−1 h−1). Characterization results demonstrated that superior catalytic activity could be achieved from large specific surface area, good reducibility and high proportion of Mn4+. Besides, high Fe contents proved beneficial in generating additional oxygen vacancies, thereby improving the performance of the catalyst. The stable crystal structures and surface electron density distributions of the catalysts, and adsorption sites of o-xylene on the catalyst surface, were also determined through density functional theory (DFT) calculations to provide an in-depth mechanism on how the o-xylene oxidation occurred. Moreover, analysis of the energy barrier during the oxidation process proved that the ring-opening reaction on the surface of Fe3Mn1-RP with an activation energy as low as 2.46 eV would more likely occur via oxygen vacancies. [Display omitted] • Homogeneously dispersed Fe3Mn1-RP exhibited superior o-xylene oxidation activity. • High Fe content resulted in more oxygen vacancies and better reducibility. • Surface electrons of Fe3Mn1-RP with less dissipation energy were more active. • O-xylene could be more stably adsorbed on "Mn + Mn" active sites. • Fe3Mn1-RP lowered energy barrier of ring-opening during o-xylene oxidation. [ABSTRACT FROM AUTHOR]

The possible effect of optimized acid sites on NH 3 -SCR performance and the fundamental mechanism are barely illustrated. In this work, we report two model catalysts of hexagonal (h-CPO) and monoclinic (m-CPO) cerium phosphate with disparate acidity that show different NH 3 -SCR activities under the same reaction conditions. Brønsted acid sites were found to be crucial for NH 3 -SCR performance at both low and high temperature. The electron localization discrepancy of h-CPO was more pronounced as compared with m-CPO, leading to the enrichment of P-OH (Brønsted acid site) which could strongly absorb NH 3 and then generate NH 4 + to participate in fast SCR via Langmuir-Hinshelwood mechanism, resulting in good activity at low temperature. The zeolitic water stored in the open channels of h-CPO could be released as supplement for P-OH sites which prevent the depletion and non-selective oxidation of NH 3 thus maintaining its high activity at high temperature via the Eley-Rideal mechanism. Meanwhile, as DFT calculation revealed, cerium is the electron deficient center which can easily fix NO and NO 2 from the intake, generating active NO 2(ad) or nitrites and facilitating fast SCR by reacting with NH 4 + species. Hence, the superior protonation ability to form P-OH and low energy barrier to generate active nitrites of h-CPO led its T 80 NO x conversion to a broaden temperature of 150–450 oC under high GHSV of 177,000 h-1. Furthermore, experimental and DFT calculation also demonstrated that the enriched Brønsted acid sites over h-CPO have largely suppressed SO 2 adsorption , thus significantly reducing the formation of metal sulfates and achieving great SO 2 resistance. The ammonium sulfate deposits can be storage of NH 3 , supplying additional reductant to promote high temperature activity and selectivity. [Display omitted] • Electron localization discrepancy was driving forces for P-OH formation. • Facile supplementation of P-OH and protonation ability contributes to high activity. • Cerium is the electron deficient center for NO 2 fixing, contributing LT NH 3 -SCR. • SO 2 -(NH 4) 2 SO 4 /NH 4 HSO 4 -SO 2 dynamic balance leads to the SO 2 /H 2 O resistance of h-CPO. [ABSTRACT FROM AUTHOR]

The possible effect of optimized acid sites on NH 3 -SCR performance and the fundamental mechanism are barely illustrated. In this work, we report two model catalysts of hexagonal (h-CPO) and monoclinic (m-CPO) cerium phosphate with disparate acidity that show different NH 3 -SCR activities under the same reaction conditions. Brønsted acid sites were found to be crucial for NH 3 -SCR performance at both low and high temperature. The electron localization discrepancy of h-CPO was more pronounced as compared with m-CPO, leading to the enrichment of P-OH (Brønsted acid site) which could strongly absorb NH 3 and then generate NH 4 + to participate in fast SCR via Langmuir-Hinshelwood mechanism, resulting in good activity at low temperature. The zeolitic water stored in the open channels of h-CPO could be released as supplement for P-OH sites which prevent the depletion and non-selective oxidation of NH 3 thus maintaining its high activity at high temperature via the Eley-Rideal mechanism. Meanwhile, as DFT calculation revealed, cerium is the electron deficient center which can easily fix NO and NO 2 from the intake, generating active NO 2(ad) or nitrites and facilitating fast SCR by reacting with NH 4 + species. Hence, the superior protonation ability to form P-OH and low energy barrier to generate active nitrites of h-CPO led its T 80 NO x conversion to a broaden temperature of 150–450 oC under high GHSV of 177,000 h-1. Furthermore, experimental and DFT calculation also demonstrated that the enriched Brønsted acid sites over h-CPO have largely suppressed SO 2 adsorption , thus significantly reducing the formation of metal sulfates and achieving great SO 2 resistance. The ammonium sulfate deposits can be storage of NH 3 , supplying additional reductant to promote high temperature activity and selectivity. [Display omitted] • Electron localization discrepancy was driving forces for P-OH formation. • Facile supplementation of P-OH and protonation ability contributes to high activity. • Cerium is the electron deficient center for NO 2 fixing, contributing LT NH 3 -SCR. • SO 2 -(NH 4) 2 SO 4 /NH 4 HSO 4 -SO 2 dynamic balance leads to the SO 2 /H 2 O resistance of h-CPO. [ABSTRACT FROM AUTHOR]

Bimetallic catalysts catalyst was potential catalyst for electrochemical reduction of CO 2 (CO 2 RR) to produce liquid fuel. Adjusting the adsorption energy of intermediates on bimetallic catalysts was very effective to improve the selectivity of electroreduction of CO 2 to low-carbon alcohols. However, it was difficult to further increase the yield of low-carbon alcohols by adjusting the content ratio between metals alone. Here, in vacuum environment, we use low temperature plasma technology to treat Ag@Cu catalyst to form Cu–CuO interface on the catalyst surface, so that the selectivity and activity of the reaction were further enhanced. The performance of CO 2 RR was effectively improved by the surface Cu–CuO interface. CO 2 RR tests show that at −0.8 V vs RHE, the faraday efficiency of low-carbon alcohols of Ag@Cu-10 catalyst was the highest of 65.5%, which was 19.9% higher than that of Ag@Cu. In addition, the linear sweep voltammetry test showed that the current density of CO 2 RR increased by 2 times, indicating that the surface Cu–CuO interface promoted the activation of CO 2 on the surface of the catalyst and improved the intrinsic activity. This work introduces a technique of preparing surface Cu–CuO interface to adjust the adsorption energy of CO 2 RR intermediates, which provides a new idea for the development of efficient CO 2 RR catalysts. • Surface Cu-CuO interface was prepared to improve the electrocatalytic activity of CO 2. • Ag@Cu exhibited excellent performance for CO 2 RR to low-carbon alcohols with FE of 65.5% at -0.8 V (vs. RHE) and current density of 13 mA·cm-2. • The synergistic effect of Ag and CuO promoted the adsorption of intermediate species. [ABSTRACT FROM AUTHOR]

Considering the disadvantages of Cu-based catalyst for acetylene hydrochlorination, such as poor dispersion, severe carbon deposition and insufficient active sites, supported Cu-complex catalysts were synthesized by using phosphine-oxide organic compounds as ligands. A local active domain was successfully constructed based on the complexation of Cu atom to heteroatomic structure in meticulously selected ligands, in which the phenyl group acts as an electron donor to change the CuCl 2 active site electronic structure. The density functional theory calculation proved the existence of a strong interaction between triphenylphosphine oxide and CuCl 2 , and synchronously, electrons on the benzene ring were transferred to the Cl atom in CuCl 2 , stabilizing the Cu species. This superior activity may be attributed to the heightened adsorption of HCl and weakened C 2 H 2 and vinyl chloride adsorption by the constructed local active domain, which impedes the carbon deposition that promotes the continuous exposure of active sites. Under the reaction conditions: T = 180 ℃, GHSV C2H2 = 180 h−1 and V HCl /V C2H2 = 1.2, the C 2 H 2 conversion of 15%Cu7%TPPO/AC reaches 88%, which was over 30% higher than 15%Cu/AC catalyst. The significantly improved activity and stability of the proposed catalyst provides a reference for green and sustainable production of vinyl chloride. [Display omitted] • Complexation of TPPO with CuCl 2 establishes a locally active domain catalyst. • 15%Cu7%TPPO/AC catalyst improves the performance over 30% than 15%Cu/AC catalyst. • Significantly improved stability endows the catalyst a bright application prospect. • The electrons transfer from the benzene ring to the Cl atom in CuCl 2. [ABSTRACT FROM AUTHOR]

In this work, a self-supporting transition metal phosphate was prepared for overall water splitting, in which Ni x Co 1-x (PO 3) 2 nanoparticles wrapped in nitrogen-doped carbon were supported on partially phosphatized foamed nickel. [Display omitted] • Self-supporting NiCoPO@NC/P-NF-e catalyst showed superior OER and wide-pH HER activity. • NiCoPO@NC/P-NF-e needed a voltage of 1.50 V to reach 10 mA cm−2 for water splitting. • Ni x Co 1-x (PO 3) 2 wrapped in nitrogen-doped carbon enhanced the stability of catalyst. The progress in the development of 3D self-supporting electrocatalysts is of great significance for the practical application of water electrolysis. In this work, a self-supporting transition metal phosphate was prepared, in which nickel–cobalt phosphate (Ni x Co 1-x (PO 3) 2) nanoparticles wrapped in nitrogen-doped carbon (NC) were supported on partially phosphatized foamed nickel (P-NF). The particles of ZIF-67-derived Co-N co-doped carbon were fixed on NF by electroplating Ni. The following phosphating led to the Ni x Co 1-x (PO 3) 2 particles wrapped in NC loading on P-NF (NiCoPO@NC/P-NF-e). The Ni x Co 1-x (PO 3) 2 nanoparticles could effectively afford active sites and exhibited preeminent catalytic activity. Also, NC could improve the electrical conductivity of the sample, accelerate the transfer and transport of charge and prevent the corrosion of electrolyte to Ni x Co 1-x (PO 3) 2 particles. The NiCoPO@NC/P-NF-e catalyst exhibited outstanding catalytic performances for oxygen evolution reaction in 1 M KOH and wide-pH hydrogen evolution reaction. A voltage of 1.50 V was required to reach 10 mA cm−2 for water splitting. Besides, the NiCoPO@NC/P-NF-e catalyst showed superior durability for electrolysis of water. The work completed in this study provides a potential methodology for preparing 3D self-supporting phosphate catalysts. [ABSTRACT FROM AUTHOR]

Fe 3 O 4 -FeC x heterojunction active site confined in N-OMC was prepared and showed excellent activity in converting CO 2 to light olefins, which was attributed to the synergistic effect of heterojunction components in RWGS–FTS reaction. [Display omitted] • Fe 3 O 4 -FeC x heterojunction active site confined in N-OMC was prepared successfully. • The catalyst showed excellent activity and stable in converting CO 2 to light olefins. • The excellent activity was attributed to the synergy of Fe 3 O 4 -FeC x heterojunction. • The influence of N-OMC and K+ on catalytic activity and selectivity was explored. • Heterojunction was in favor of high yield of light olefins and low selectivity of C 1. Converting CO 2 into light olefins is full of challenges and opportunities, which was limited by poor activity catalysts. Herein, Fe 3 O 4 -FeC x heterojunction active site confined in N-doped graphene shell was synthesized on the surface of N-OMC. Alkali metal and N atom was used for modifying the surface electron density, which could suppress the excessive hydrogenation of CH x and improve the adsorption of CO 2 , thus increasing the yield of light olefins. The 0.8Fe-0.1K@N-OMC showed CO 2 conversion of 54.5%, C 2 =–C 4 = selectivity of 65.63%, and a stability of 100 h (3.0 MPa, 320 °C, and GHSV = 4800 mL/g cat /h). The reaction mechanism was investigated using various characterization techniques, which demonstrates that the excellent catalytic active was originated from Fe 3 O 4 -FeC x heterojunction. The CO was first produced by the RWGS reaction catalyzed by Fe 3 O 4 , and then converted to light olefins on the neighboring FeC x active site by FTs reaction. Confinement effect of N-doped graphene shell inhibits the reoxidation and agglomeration of heterojunction active components, which boosts the catalyst' stability. This work proposes a simple and feasible synthesis strategy to construct Fe 3 O 4 -FeC x heterojunction catalysts, which provides insights into catalysts design and the reaction mechanism of CO 2 conversion to light olefins. [ABSTRACT FROM AUTHOR]

[Display omitted] • The alkynes provide a platform to obtain site-isolated and unsaturated metal sites for catalytic application. • The alkyne is firstly introduced into the UiO-66-type metal-organic frameworks (UiO-66-alkyne). • The catalytic site of Ni is incorporated into MOF-alkyne by bonding with terminal alkynyl groups. • Ni-UiO-66-alkyne shows excellent catalytic performance and the promising industrialization characteristics. Electron-donating groups in the robust MOF motif are able to provide an excellent catalytic platform, therefore obtaining site-isolated metal sites. In this study, the terminal alkyne is firstly introduced into UiO-66-type metal-organic frameworks (UiO-66-alkyne). Herein, to further study the application potential of this material, a covalently bonded nickel catalyst based on the alkynyl-tagged UiO-66-alkyne has been prepared and afforded us unprecedented highly dispersed and highly efficient catalytic active species. Meanwhile, this nickel-contained catalyst method for joining metals provided an alternative pathway regarding catalyst designing. With UiO-66-alkyne-Ni, the heterogeneous transformation of homogeneous catalysts is realized. Using benzaldehyde and malononitrile as starting materials, we were able to catalyze the Knoevenagel condensation within 45 min under room temperature with yield (> 99 %). Moreover, the recovery rate of the UiO-66-alkyne-Ni also outperformed previous MOFs in both small-scale and gram-level reactions, which shows UiO-66-alkyne-Ni is a potential contributor to the subsequent industrialization. [ABSTRACT FROM AUTHOR]