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Micro Fuel cells or microfluidic fuel cells (μMFCs) are one of the most promising power supplies for portable electronics. However, the necessary electrode spacing is required to prevent fuel-crossover and maintain the stable operation, introducing the unavoidable ohmic resistance and retarding the miniaturization. Herein, we propose a novel μMFC device combining the cellulose paper as separator, with selective catalysts at the cathode side to eliminate the unwanted side reactions and increase the system compactness. One single reactant solution containing fuel and electrolyte is applied to keep the device stable operation. The power-generation properties are evaluated in typical alkaline conditions. A great construction simplification makes the device a substantial high-power density of 2.14 W cm−3 and maximum current density of 15.82 A cm−3. The μMFC stacks are arranged in series and parallel manners, which delivers a maximum power output of 23.6 mW and current of 194.6 mA. It is expected that innovative and customizable performance from commercial paper and low-cost carbonaceous catalysts can provide a forum for future advancement in chip-based electrochemical energy generation and storage devices. • Filter paper served as a membrane for μMFC is proposed. • The electrode-pair distance is greatly minimized (∼140 μm). • The optimized μMFC delivers an ultrahigh power density of 2.14 W cm−3. • The μMFC stacks power output of 23.6 mW and current output of 194.6 mA are achievable. [ABSTRACT FROM AUTHOR]

The electrochemical carbon dioxide reduction reaction (CO2RR) holds substantial promise for producing high‐value chemicals and fuels, drawing significant attention from both academia and industry. This work proposes an in‐situ electrodeposition method to prepare indium‐doped copper (Cu)‐based catalysts on carbon paper (Cu100Inx−CP, x=3.9, 4.5, 4.8, 5.1, and 7.6, denoting the molar ratio of In to Cu in the catalyst.). The catalysts Cu100Inx−CP were used for CO2RR to produce multi‐carbon (C2+) products. Characterization results showed that In was highly dispersed in the Cu particles at x<5.1. The Cu100In5.1−CP (containing 0.95 wt % In based on Cu) was very efficient for electrocatalytic CO2RR. The in‐situ Raman spectroscopy showed that Cu100In5.1−CP enhanced *CO intermediate adsorption and promoted the production of C2+ products due to the synergistic effect between In and Cu. In doping could suppress HER, enhanced *CO intermediate adsorption, and C−C coupling for the production of C2+ products in CO2RR. [ABSTRACT FROM AUTHOR]

Conventional Al‐air batteries are not suitable as portable power devices due to their complicated water management and bulky system. To resolve this issue, the fiber paper‐ and cotton cloth‐based Al‐air batteries were proposed, which exploited the capillary force from the paper (FP) and cotton cloth (CC) to deliver the solutions and eliminated the external pump. The physical features of the FP and CC were gained including the surface morphologies, surface elementary analysis, liquid absorption and flow rates. CC owned larger liquid absorption and faster flow rate due to its hierarchically woven‐spun fiber structure, compared to the randomly oriented fibers of the FP, although the surface of the CC demonstrated lower O/C ratio than that of the FP. So, the performance of the CC‐based Al‐air battery was largely higher than that of the FP‐based battery. The performance of the CC‐based Al‐air battery was optimal at 1.0 M NaOH electrolyte and the anode‐to‐cathode surface area ratio of 1 : 4, with the peak power density of 14.95±0.28 mW cm−2, and the maximum current density of 36.61±0.54 mA cm−2. To apply the CC‐based Al‐air battery, the two‐battery pack connected in series was assembled to drive a timer and light 9 LEDs. [ABSTRACT FROM AUTHOR]

Fibers represent a type of structure of great interest in catalysis since they combine high area to volume ratio and can be fabricated from many types of materials, such as ceramic oxides, polymers, and alloys. They can be used in isolated form or structured, as in the case of the ceramic papers synthesized in this work, following a modified papermaking technique. The addition of cationic and anionic polyelectrolytes improved the retention of ceramic fibers during the ceramic paper formation stage by adsorption processes, through the formation of floccules. In the complex aqueous system containing charged macromolecules, the amounts of polyelectrolytes to be added were determined by titrations. To enhance mechanical properties of ceramic papers, different classes of nanoparticle suspensions can be used as binders. As a novel alternative, we have used different borate-type compounds. Among them, we selected natural ulexite, which was purified and used as a binder of ceramic fibers. In order to improve mechanical resistance and flexibility, measured from tensile indexes and elastic module, the amounts of NaCaB5O6(OH)6.5H2O and the calcination temperature were varied. In this contribution, to take advantage of the unique characteristics of the ulexite-containing ceramic papers, they were impregnated with Co,Ce and Co,Ba,K and tested for diesel soot combustion. [ABSTRACT FROM AUTHOR]

The present study reports the catalytic activity and stability of Mn–Ce catalyst with low Mn content in the soot combustion reaction. Through X-ray diffraction analysis (XRD), Laser Raman Spectroscopy (LRS), and Temperature-Programmed Reduction studies (CO-TPR), it is inferred that the Mn/(Mn + Ce) ratio = 0.1 allows the formation of a solid solution between Mn and Ce oxides with high catalytic performance. This formulation was structured over ceramic papers to conform catalytic ceramic papers. These structured fibrous catalysts presented high catalytic stability after several cycles of the soot combustion reaction and they prove to be highly active in the reaction of interest. Their catalytic performance under different oxidation conditions was also evaluated by varying the NO and O2 proportion in the gas feed. The NO content in the gas feed considerably influenced the catalytic performance and the reaction order with respect to this oxidant was ca. 0.3. The activation energy was found to be 14 kcal/mol. [ABSTRACT FROM AUTHOR]

• The hygroscopic property of paper fiber is used to prepare a bifunctional catalyst. • The impregnation time for preparing the hollow microtubular Ni-MgO-CaO is 1 min. • 94.1 % of hydrogen is stably produced on 5Ni-10MgO-CaO from biogas for 50 cycles. • Only 37.1 % loss of the sorption-enhanced effect is shown during the entire cycle. Sorption-enhanced steam reforming (SESR) process is a promising technology aiming at the production of high purity hydrogen with CO 2 capture. The key to the success of this process is the availability of high-performance bifunctional catalysts. Herein, we develop a hollow microtubular Ni-MgO-CaO bifunctional catalyst with paper fiber as template. Due to the strong hygroscopic properties of paper fibers, it provides a method for the rapid synthesis of catalysts with design components by adsorbing solution. The characterizations indicate that the impregnation time (1 min vs 24 h) has no effect on the structural properties of Ni-MgO-CaO bifunctional catalysts. MgO as an inert spacer can weaken the sintering of CaO to ensure a stable CO 2 uptake. Moreover, the agglomeration of Ni particles is inhibited by the MgO coating on their surface. 5Ni-10MgO-CaO as the best performing catalyst displays high stability for the SESR of biogas (SESRB) reaction, during which 94.1 % purity of hydrogen with a 95.2 % conversion of CH 4 is stably produced and only 37.1 % decrease of sorption-enhanced effect is observed in 50 SESRB-calcination cycles. [ABSTRACT FROM AUTHOR]

The metal-organic frameworks (MOFs) nanozyme-mediated paper-based analytical devices (PADs) have shown great potential in portable visual determination of phenolic compounds in the environment. However, most MOF nanozymes suffer from poor dispersibility and block-like structure, which often prompts deposition and results in diminished enzymatic activity, severely hindering their environmental applications. Here, we proposed colorimetric PADs for the visual detection of dichlorophen (Dcp) based on its significant inhibitory effect on the two-dimensional (2D) MOF nanozyme activity. Specifically, we synthesized a 2D Cu TCPP (Fe) (defined as 2D-CTF) MOF nanozyme exhibiting excellent dispersibility and remarkable peroxidase-like (POD-like) activity, which could catalyze the oxidation and subsequent color change of 3,3′,5,5′-tetramethylbenzidine even under neutral conditions. Notably, the POD-like activity of 2D-CTF demonstrated a unique response to Dcp because of the occupation of Fe–N 4 active sites on the 2D-CTF. This property enables the use of 2D-CTF as a highly efficient catalyst to develop colorimetric PADs for naked-eye and portable detection of Dcp. We believe that the proposed colorimetric PADs offer an efficient method for Dcp assay and open fresh avenues for the advancement of colorimetric sensors for analyzing of phenolic toxic substances in real samples. [ABSTRACT FROM AUTHOR]

A series of thin Pt-Co films with different metal ratios were deposited by using the sequential cosputtering directly on a commercial hydrophobic carbon paper substrate at room temperature and in ultra-high vacuum (UHV) conditions. Their electrocatalytic properties toward the oxygen reduction reaction were investigated in 0.5 M H2SO4 solution by means of cyclic voltammetry (CV) and linear sweep voltammetry (LSV) on rotating disc electrode (RDE). The results showed that Pt particles, deposited by dc-magnetron gun, surround the large Co-clusters deposited by rf-magnetron gun. In addition, the increase of Co content led to an increase in the electrochemical active surface area (EASA) from 23.75 m2/gPt to 47.54 m2/gPt for pure Pt and Pt:Co (1:3), respectively, which corresponded the improvement of the utilization of Pt by a factor of 1.91. This improvement indicated that the sequential magnetron cosputtering was one of the essential technique to deposit homogeneous metal clusters with desirable size on the gas diffusion layer by adjustment plasma parameters. [ABSTRACT FROM AUTHOR]

In this study, hydrogen harvesting from fermentation of sugarcane bagasse (SCB) was promoted by maintaining synergism between sulfonated graphene (SGR) catalyst and paper mill sludge (PMS). The sulfonic acid (–SO 3 H) groups in the catalyst played a major role in destructing the β-1,4 glycosidic bonds of sugarcane bagasse, releasing readily biodegradable sugars into the fermentation medium. The cellulose, hemicellulose, and lignin conversion efficiency were improved by 127.5%, 495.0%, and 109.2%, respectively with 20 mgSGR/gVS catalyst addition, compared with the control samples. These values were also higher than those obtained by non-sulfonated graphene catalyst. The hydrogenation of sugarcane bagasse was maximized at a sulfonated graphene catalyst dosage of 60 mgSGR/gVS, providing the highest hydrogen harvesting of 4104 ± 321 mL. This was associated with an increase of the Proteobacteria phyla up to 52.0%, Firmicutes phyla to 13.9%, and Acinetobacter sp. to 39.8% compared with only 37.0%, 11.3% and 11.1% in the control assay respectively. Moreover, sulfonated graphene catalyst supplementation promoted the acetate fermentation reaction pathway by increasing the acetate/butyrate ratio up to 4.1. Nevertheless, elevating the catalyst dosage up to 120 mgSGR/gVS reduced the hydrogen harvesting (1190 ± 92 mL) due to the release of furfural (1.76 ± 0.02 g/L) in the fermentation cultures, deteriorating the microbes' internal composition and metabolism bioactivities. Finally maximizing the hydrogen productivity from sugarcane bagasse is feasible by incorporation of paper mill sludge and sulfonated graphene catalyst at dosage not exceeding 60 mgSGR/gVS. However, investigating the recyclability and disposal of digestate containing sulfonated graphene catalyst and the associated economic feasibility needs more attention in the future. [Display omitted] • Sugarcane bagasse was fermented by paper mill sludge supported on sulfonated graphene. • Synergism between paper mill sludge/sulfonated graphene improved bio-H 2 by 4.8 times. • Sulfonated graphene promoted acetate fermentation (HAc/HBu of 4.1) and inhibited HPr. • Acinetobacter degrading phenol increased by 3.6 folds with sulfonated graphene catalyst. • MolDock visualized H-bonding in hydrogenase protein/sulfonated graphene interaction. [ABSTRACT FROM AUTHOR]

In this work, the performance of residual iron dust (RID) from metallurgic industry was assessed as Fenton catalyst for the treatment of real pulp bleaching wastewater. The focus was on the removal of recalcitrant pollutants AOX (adsorbable organic halides), by a novel, cleaner, and cost-effective circular solution based on a waste-derived catalyst. The behaviour of RID as iron source was firstly assessed by performing leaching tests at different RID:wastewater w/v ratios and contact time. Afterwards, RID-catalysed homogeneous and heterogeneous Fenton processes were conducted to maximise AOX removal from the pulp bleaching wastewater. Reusability of RID was assessed by a simple collect-and-reuse methodology, without any modification. Similar AOX removal under less consumption of chemicals was achieved with the novel heterogeneous Fenton process. Reaction in the bulk solution was the main pathway of AOX removal, given that the low surface area and porosity of the material did not allow for a high contribution of surface reaction to the overall performance. Moreover, AOX removal was similar over two consecutive treatment cycles, with Fenton process being responsible for 56.7–62.1% removal of AOX from the wastewater, and the leaching step adding 11.4–13.2%. At the end of treatment, COD either decreased (1st cycle) or remained unchanged (2nd and 3rd cycle). The operating cost of the optimised heterogeneous Fenton was 3–11% lower than under conventional Fenton process. This work presented a novel, circular solution based on a low-cost waste-derived catalyst, advancing the knowledge needed to foster industrial application of such technologies to increase industrial environmental performance and efficiency. [Display omitted] • Residual iron dust successfully catalysed Fenton process, acting mainly as iron supplier. • Catalyst performance in removing AOX was maintained over consecutive treatment cycles. • The catalyst was successfully reused without any modification or regeneration. • Operating cost of the heterogeneous Fenton was 3–11% lower than conventional Fenton. [ABSTRACT FROM AUTHOR]

Hallmark of a successful catalyst is its high efficiency, economic aspects, operational simplicity, extensive reusability, higher environment friendliness, and potential use in multiple industrial applications. Herein, a facile protocol involving a catalyst with Pd nanoparticles supported on cellulose paper (also known as a "dip‐catalyst") for the hydrogenation of a series of quinolines, nitroarene, and C−C bond formation reactions in most benign solvents such as water is described. The mere insertion/removal of the "dip‐catalyst" strip enables instantaneous start/stop of the reaction, which enhances its reusability and ease of separation of products. Cellulose paper (CP) strips decorated with Pd nanoparticles (Pd/CP) are prepared by the reduction of K2PdCl4 soaked strips using formic acid as reductant. The resulting spherical shaped Pd particles, confirmed by scanning electron microscopy, form stable catalysis centers on the support. XRD signature confirms the crystallinity of the Pd nanoparticles and the TEM images display 15–20 nm size particles uniformly decorating CP. X‐ray photoelectron spectroscopy indicates the formation of metallic Pd. The catalyst is tested for the C−C bond formation reactions. Pd/CP catalyzed Suzuki‐Miyaura coupling reaction demonstrate >99% conversion with optimum selectivity. On the other hand, Mizoroki‐Heck reaction produced 87% conversion with the reaction of 4‐methoxycarbonyl phenylboronic acid and iodobenzene in ethanol:water (1 : 1 v/v) using KOH as base. The developed Pd/CP construct produces >99% of the pyridine‐ring hydrogenated product on quinoline hydrogenation using tetrahydroxydiboron (THDB) as the hydrogen source. Diverse and highly reducible functional groups were also evaluated for transfer hydrogenation, which demonstrates a high efficiency in terms of both reactivity and selectivity. The used catalysts are recyclable for the multiple cycles. [ABSTRACT FROM AUTHOR]

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A combination of multiple methods can greatly intensify the removal efficiency of hazardous substances. Herein, the synergistic utilization of adsorption and catalysis achieved for the highly efficient removal of hexavalent chromium (Cr6+). A paper-based palladium nanoparticles/UiO-66-NH 2 (PdNPs/UiO-66-NH 2 /LP) composite catalyst was prepared using lignocellulose paper-based material (LP) for the loading of UiO-66-NH 2 MOFs materials, with the lignin in LP as the reducer for the in-situ synthesis of PdNPs (12.3 nm) on UiO-66-NH 2 MOF materials. Lignocellulose paper-based materials with high strength (82 N·m/g) realized low-cost and environmentally friendly preparation and guaranteed the practicability of PdNPs/UiO-66-NH 2 /LP composite catalyst. The prepared PdNPs/UiO-66-NH 2 /LP achieved high-efficiency catalytic activity for hazardous Cr6+ removal through a constructed adsorption-catalytic synergistic system, in which the removal efficiency of Cr6+ in 10 min was increased by 2 times compared with a composite catalyst without MOFs loading. Finally, the PdNPs/UiO-66-NH 2 /LP composite catalyst demonstrated the great efficiency and practicality of water pollution treatment through synergistic adsorption enrichment and catalytic reduction. [Display omitted] [ABSTRACT FROM AUTHOR]

Sluggish CO2 reduction reaction (CO2RR) and evolution reaction (CO2ER) kinetics at cathodes seriously hamper the applications of Li-CO2 batteries, which have attracted vast attention as one kind of promising carbon-neutral technology. Two-dimensional transition metal dichalcogenides (TMDs) have shown great potential as the bidirectional catalysts for CO2 redox, but how to achieve a high exposure of dual active sites of TMDs with CO2RR/CO2ER activities remains a challenge. Herein, a bidirectional catalyst that vertically growing MoS2 on Co9S8 supported by carbon paper (V-MoS2/Co9S8@CP) has been designed with abundant edge as active sites for both CO2RR and CO2ER, improves the interfacial conductivity, and modulates the electron transportation pathway along the basal planes. As evidenced by the outstanding energy efficiency of 81.2% and ultra-small voltage gap of 0.68 V at 20 µA cm-2, Li-CO2 batteries with V-MoS2/Co9S8@CP show superior performance compared with horizontally growing MoS2 on Co9S8 (H-MoS2/Co9S8@CP), MoS2@CP, and Co9S8@CP. Density functional theory calculations help reveal the relationship between performance and structure and demonstrate the synergistic effect between MoS2 edge sites and Co9S8. This work provides an avenue to understand and realize rationally designed electronic contact of TMDs with specified crystal facets, but more importantly, provides a feasible guide for the design of high-performance cathodic catalyst materials in Li-CO2 batteries. [ABSTRACT FROM AUTHOR]

Solid oxide fuel cells (SOFCs) can accept a direct feed of biogas for power generation; however, carbon deposition is a major obstacle to their practical application. When a paper‐structured catalyst (PSC) with a dispersion of Ni‐loaded flowerlike Ce0.5Zr0.5O2 (Ni/CZ(F)) was applied to the anode of an electrolyte‐supported cell (ESC), the open‐circuit voltage of the cell directly fed simulated biogas was increased from 0.87 to 0.98 V at 750°C. The rates of cell‐voltage degradation and coke formation of the ESC with the Ni/CZ(F)‐PSC during 100 h of operation were 4.3% kh−1 and 0.43 mg‐C g‐PSC−1 h−1, respectively, which were lower than those of an ESC with a Ni‐loaded PSC without the CZ(F) dispersion (10.4% kh−1 and 8.1 mg‐C g‐PSC−1 h−1, respectively). This performance improvement is attributed to the unique porous morphology and high oxygen storage capacity of CZ(F), which can contribute to the prevention of Ni agglomeration and the removal of coke from the catalyst surface, respectively. Thus, the Ni/CZ(F)‐PSC can function as a practically applicable reforming domain for an internal‐reforming biogas‐fueled SOFC. [ABSTRACT FROM AUTHOR]

In this paper, ceria flowers containing nano-sized catalyst Ni particles were prepared on alumina-silica fiber network for production of hydrogen from biogas. The CeO 2 flowers were prepared using hydrothermal method and then NiO was loaded on the CeO 2 flowers by impregnation method. The Paper-structured catalysts (PSCs) were prepared from alumina-silica fibers and the CeO 2 –NiO flowers using conventional paper making method. The loaded NiO particles were uniformly dispersed on the CeO 2 flowers with the use of polyvinylpyrrolidone as a dispersion enhancer, which was observed by FE-SEM and EDX analysis. The NiO particles were then reduced into Ni by using H 2. The PSCs containing CeO 2 –Ni flowers with various Ni contents (2.1, 3.4, and 4.6%) were used for dry reforming of CH 4. It was found that 3.4% amount of Ni on the PSC was suitable for reforming reaction, and the higher amount of Ni (4.6%) did not increase the CH 4 conversion. The PSC with the CeO 2 flowers had porous structure and large surface area leading to the better dispersion of the Ni particles with smaller size. This helped increase in catalytic performance, prevention of agglomerated particle catalysts at high temperature and coke forming after a long time operation. The CH 4 conversion of the PSCs containing CeO 2 –NiO flowers in the dry reforming of CH 4 was much higher (nearly 90%) with a smaller Ni content in comparison with the PSC without the CeO 2 flowers (with higher Ni content of 8.6%). Moreover, the PSCs with the flowers exhibited an excellent catalytic stability with the degradation of CH 4 conversion of only 3.1% after 50 h of reforming. In addition, the high oxygen storage capacity and oxygen mobility of CeO 2 resulted in a partial removal of coke forming on the catalyst particles during reforming. This indicated that the catalytic activity of the Ni particles dispersed on the CeO 2 flowers for dry reforming of CH 4 was superior to that of various Ni-based catalyst systems which had much higher Ni contents. Therefore, it is possible to use the PSCs containing CeO 2 –Ni flowers to generate hydrogen for use as fuels from dry reforming of CH 4. Image 1 • 5 μm spherical CeO2 flowers had open porous structure and high surface area. • NiO particle catalysts were uniformly dispersed on the CeO2 flowers. • Paper-structured catalysts (PSC) with the dispersed flowers had a great porosity. • PSCs with small Ni content exhibited excellent catalytic activity in CH4 reforming. • PSCs exhibited degradation of CH4 conversion of only 3.1% after 50 h of reforming. [ABSTRACT FROM AUTHOR]

This study reports the synthesis of bacterial cellulose (BC) hydrogel sheets and their utilization as a support for silver‑nickel oxide nanocomposites (Ag/NiO). A two-step facile hydrothermal method was employed for the preparation of Ag/NiO, followed by impregnation into BC hydrogel sheets. A 20% Ag/NiO composition was revealed by dry weight analysis. The stability of nanocomposites-Hydrogel was confirmed by Ag+ and Ni2+ ion release study. The catalytic activity of the BC-Ag/NiO was evaluated against chemical reduction of congo red, methyl orange and methylene blue. The reduction reaction followed pseudo first order kinetics and k app values of 0.1147 min−1, 0.1323 min−1 and 0.12989 min−1 were obtained for CR, MO, and MB dyes, respectively. The BC-Ag/NiO catalyst could be easily recovered and re-used in another reaction without centrifugation. The synthesized nanocomposites hydrogel was also tested for its antibacterial activity against Gram-negative bacteria, Escherichia coli (E.coli) and Gram-positive bacteria, Staphylococcus aureus (S.aureus). [ABSTRACT FROM AUTHOR]

The electrochemical activity of catalysts strongly depends on the uniform distribution of monodisperse Pt nanoparticles without aggregates. Here, we propose a new hydrolysis-assisted smearing method for Pt loading on a free-standing paper-type electrode. Polyacrylonitrile (PAN)-based nanofiber paper was used as the electrode, and it acted as a Pt support. Hydrolysis of the electrode tripled the number of active nucleation sites for Pt adsorption on the PAN nanofibers, thereby significantly enhancing the wettability of the nanofibers. This facilitated the uniform distribution of Pt nanoparticles without aggregate formation up to 40 wt% (about 0.8 mg/cm2) with a particle size of about 3 nm. The catalytic current of the hydrolyzed Pt electrode in CH3OH/H2SO4 solution exceeded 213 mA/cm2 Pt mg, which was considerably greater than the current was 148 mA/cm2 Pt mg for an unhydrolyzed electrode. [ABSTRACT FROM AUTHOR]

In this study, we report the findings that the C-N composites containing Ni and Co (Ni1Co1/C-N, Ni3Co1/C-N, Ni6Co1/C-N, Ni9Co1/C-N, NiCo0/C-N and Ni0Co/C-N) can be produced by direct pyrolysis of the NiCo-doped polyaniline (PANI) precursors in N2 atmosphere at 800C and show efficient electroactivity for oxygen reduction reaction (ORR) in alkaline media. Distribution and compositions of the catalysts were characterized by SEM, TEM, EDS and XRD techniques. The catalysts were loaded on carbon paper to prepare gas diffusion electrodes, in which electrocatalytic activity for ORR in alkaline media was investigated by voltammetric techniques. The ORR current density on these carbon paper-supported NiCo/C-N catalysts exhibits a linear increase with the negative shift of ORR potential. The ORR onset potential is around 0.2V (versus Ag/AgCl) in alkaline media. Among the prepared catalysts, the catalyst Ni6Co1/C-N presents the largest ORR current density, which is 68.5mAcm@0.8V (versus Ag/AgCl) in alkaline media. Moreover, Ni6Co1/C-N catalyst also presents good electrocatalytic activity stability for ORR. Ni/Co-doped C-N nanocomposite catalysts were prepared by direct pyrolysis of the mixture containing Ni/Co salts and polyaniline. The electrochemical test mold was used to study the ORR activity of the catalysts NiCo/C-N loaded on carbon paper. One side of the carbon paper modified with catalyst was in contact with the electrolyte while the other side was in contact with air. Among the prepared catalysts, the Ni6Co1/C-N catalyst shows the largest ORR current density of 68.5 mA cm-2@-0.8 V and high activity stability of ORR in alkaline media. [ABSTRACT FROM AUTHOR]

Rhodium as a national strategic reserve metal, has the irreplaceable role of other metals, but its resources are mainly concentrated in some countries in South Africa, and rhodium resources are very scarce in our country. In the process of industrialization in China, a large number of rhodium-containing homogeneous spent rhodium catalysts are produced, of which rhodium content is much higher than that of ores, so it is particularly important to recover rhodium from rhodium-containing homogeneous spent catalysts. By referring to the relevant literature, this paper summarized the recycling methods and prospected its prospects. [ABSTRACT FROM AUTHOR]

Co3O4 was synthesized on carbon paper (CP) using a facile method to improve electrochemical nitrate-toammonia conversion efficiency. The resulting Co3O4-CP electrode demonstrated an exceptional Faradaic efficiency of almost 100% across a broad range of application conditions, with a peak NH3 yield of 3.43 mmol h-1 cm-2 (2.25 mol gCo-1 h-1). [ABSTRACT FROM AUTHOR]

Molybdenum disulfide (MoS2) or tungsten disulfide (WS2), as a promising catalyst, is widely investigated for hydrogen evolution reaction (HER). In this work, a composite electrocatalysts MoxW1-xS2 is successfully decorated on carbon fiber paper (CFP) through a facile hydrothermal method. The three-dimensional porous CFP can enable the diffusion and penetration of electrolyte. Comparing with MoS2 and WS2 catalyst, the composite electrocatalyst MoxW1-xS2 nanosheets can expose the large number of electrochemically active sites. Hence, the as-prepared MoxW1-xS2/CFP (3:1) exhibit the outstanding HER catalytic activity with the small Tafel slope of 68 mV dec−1 and the low overpotential of − 178.4 ± 0.5 mV at a current density of 10 mA cm−2. Chronoamperometric current test for 18 h confirm the long-term stability of the composite electrocatalyst. [ABSTRACT FROM AUTHOR]

A scalable, and cost-effective method was employed to prepare self-supported CuSn bimetallic catalyst on carbon paper. The obtained CuSn catalyst demonstrates high faradaic efficiency of CO around or above 90% at a broad potential range from −0.7 to −1.8 V vs. reversible hydrogen electrode, greatly surpassing Cu or Sn counterparts. [ABSTRACT FROM AUTHOR]

Achieving an efficient catalyst in the ATRP system with a simple design, preparation from available materials, and high recyclability is a significant challenging issue. To attain the goal, herein, we used chitosan (CS)-modified cellulose filter paper (FP) as a green support for the synthesis of dip catalyst. The preparation of this catalyst involved surface treatment of the FP strips by CS coating through a dipping method, which increased the affinity of the substrate for adsorbing copper ions in the next step. The Cu@CS-FP catalyst was prepared without the requirement of any ligands. The synthesized dip-catalyst, in the form of the strips, was employed for the first time in the ATRP reaction of methyl methacrylate to assay catalytic activity. Catalytic insertion/ removal (ON/OFF) experiments were carried out during the polymerization. A reasonable control over the molecular weight with high conversion (68%) and polydispersity index of 1.32 under mild reaction conditions were obtained. Significantly, because of the facile separation of the catalyst, the amount of copper that remained in the polymer was very low (2.7 ppm). Also, the recyclability of the catalyst was investigated for five runs. The conversion in the final run was 64% without a loss of catalyst efficiency. [ABSTRACT FROM AUTHOR]

A rapid in situ analytical method was developed for the detection of generated carcinogenic aromatic amines from banned azo dyes utilizing a photocatalytic reduction-based liquid microjunction surface sampling (LMJSS)–mass spectrometry (MS) system. We utilized photocatalytic reduction under UV irradiation with TiO2 as catalyst to have rapid and mild reduction of azo dyes. The reaction conditions were optimized to have complete photocatalytic reduction within 2–5 min in pure methanol at room temperature. TiO2 was immobilized in the inner wall of the capillaries in the LMJSS system to achieve in situ sampling–online rapid reduction–MS detection for aromatic amines originating from azo dyes in packaging surface. The yields of in-tube photocatalytic reduction were near 100% by delivering the azo dye extracts through the capillary at 1 μL/min under UV irradiation. With this design, in situ analysis was completed within 2 min via direct MS detection and 7 min via liquid chromatography (LC)–MS detection. The detection limits for five aromatic amines originating from four different azo dyes were in the range of 1–17 mg/kg with relative standard deviations (RSDs) < 8.5%. In the application of the new method, four carcinogenic aromatic amines were detected and identified in three commercial packaging materials, and the quantitation results were comparable with those obtained by the conventional chemical reduction–LC–MS method (relative recovery, 81–121%). Moreover, due to the spatial resolution of the present method with a flow probe, MS imaging was achieved demonstrating clear azo dye patterns of a lab-made sample. [ABSTRACT FROM AUTHOR]

Paper has become the basic elixir in everyone's activities and usage of paper has increased day by day, the waste generated by paper is also enormous. The primary source of paper is wood (tree) yet, waste paper is environmentally good and biodegradable; however, it is the primary source of deforestation. Current research aims to find an alternate way to recycle paper in the biological approach. Hence in our work, twelve cellulose-producing bacteria were isolated, out of which one bacterial strain proved to be the best. Cellulase enzyme was extracted and purified, and used for enzymatic de-inking of photocopy papers. The optimal conditions for cellulase synthesis were at 60 °C, glucose as the only carbon source, and potassium nitrate as the nitrogen source. The enzyme demonstrated excellent de-inking at a lower pulp consistency of 3% with a 20% enzyme dose. The cellulose and hemicellulose levels decreased, which can be attributed to fiber breaking. Further, the changes in the functional groups identified by Fourier-transform infrared spectroscopy analysis and the changes in the surface morphology of the pulp fibers were obtained using scanning electron microscope analysis. [Display omitted] • The microbial cellulase enzyme produced was effective in the deinking process. • Bacillus wiedmannii was molecularly characterized, it generated 0.0591U/ml cellulase enzyme. • This work demonstrated that 3% of paper pulp could be handled with a 20% enzyme dose. • Bio-deinking is a new and unexplored method with a promising future. [ABSTRACT FROM AUTHOR]

Three types of carbon nanotubes coated on paper-like sintered stainless steel fibers (PSSF) were synthesized and applied for continuous catalytic wet hydrogen peroxide oxidation (CWPO) of phenol. The novel metal-free nitrogen-doped carbon nanotube-coated PSSF catalyst (N-CNTs/PSSF) was designed by direct chemical vapor deposition using melamine as solid precursor for the first time, and CNTs/PSSF and Fe2O3-deposited CNTs/PSSF (Fe-CNTs/PSSF) catalysts were synthesized for comparison. Characterization results showed that all the catalysts exhibited three-dimensional networks structure, with nanotubes wrapping on the stainless steel fibers successfully, and the N-CNTs showed distinct irregular corrugated morphology with nitrogen-doping level about 5.18 at.%. CWPO of phenol revealed that the N-CNTs/PSSF catalyst achieved favorable catalytic activity and highest stability during 100-h reaction (phenol and TOC conversions reached about 90% and 50%, respectively), while phenol conversions of CNTs/PSSF and Fe-CNTs/PSSF catalysts decreased over time to 72% and 58%, respectively. The N-CNTs/PSSF catalyst also showed the lowest Fe weight loss ratio (about 2.44 wt%) among the three catalysts. The favorable catalytic results of N-CNTs/PSSF can be ascribed to the synergistic effects of the strong affinity toward polar molecules of N-CNTs, as well as the enhancement in contact efficiency associated with three-dimensional networks structure of the PSSF. [ABSTRACT FROM AUTHOR]

Urgent need for waste disposal and renewable energy have opened up promising pathways for renewable and sustainable fuel production to substitute traditional fossil fuels. In this study, catalytic co-pyrolysis of waste paper (WP) and polyvinyl chloride (PVC) as typical municipal solid wastes was experimentally investigated towards hydrogen-rich syngas production. Results indicated the maximum H 2 yield (429 μmol·g cat −1·min−1) was obtained with 60% PVC weight ratio under 900 °C which was higher than single component pyrolysis. Higher hydrogen yield (681.76 μmol·g cat −1·min−1) appeared over Fe/CeO 2 –CaO under the optimal conditions compared to that of Ru/ZSM-5-CaO (445.54 μmol·g cat −1·min−1). From the calculated non-isothermal kinetic parameters, both catalysts could reduce activation energies. Proper porous structure and CaO content in the catalyst could enhance hydrogen production via carbon species fixation. • Catalytic co-pyrolysis of waste paper and PVC blends for hydrogen production is firstly investigated. • Enhanced interactions of PVC/waste paper during pyrolysis was found for H 2 production. • Non-isothermal kinetics were implemented to evaluate catalytic co-pyrolysis. • High H 2 yield was obtained over Fe/CeO 2 –CaO for its pore structure and sorption enhancing effect. [ABSTRACT FROM AUTHOR]

Highly efficient and durable anode electrocatalysts are the key to boost the performance of direct organic-molecule fuel cells (DOMFCs), yet there are still many challenges need to be solved. The PdPt alloy nanocrystals have been regarded as the most promising anode catalysts of DOMFCs, and the further improvement of their catalytic performance has attracted much attention. The effective routes includes tailoring the surface structure and optimizing the alloy composition of PdPt nanocatalysts. The high-index faceted structures possess high density of terraces and atomic steps which are efficient for electrooxidation reactions of small organic-molecule fuels, such as formic acid and ethanol. In particular, electrochemically-controlled synthesis methods present unique advantages in achieving such high-index faceted nanostructures. The current paper reports a direct electrodeposition of PdPt concave nanocubes on carbon paper (denoted as PdPt-CNC/CP). The prepared PdPt-CNC/CP has high-index faceted surface structures varying from {610} to {830}. When served as electrocatalysts, the PdPt-CNC/CP brings in outstanding mass specific activity and durability towards both formic acid oxidation reaction (FAOR) and ethanol oxidation reaction (EOR). More importantly, the selectivity of complete oxidation pathway through the cleavage of C-C bond on PdPt-CNC/CP during EOR in alkaline solution has been confirmed through NMR analysis. Based on the convenient method of direct electrodeposition of PdPt concave nanocubes on carbon paper and their excellent catalytic activity and durability, the PdPt-CNC/CP catalysts have potential advantages in being used as catalyst layers directly for membrane electrode assembly (MEA) in fuel cells, due to the reduced catalyst loading and simplified assembly process in comparison with traditional preparation procedure. Image 1 [ABSTRACT FROM AUTHOR]

Magnetically recyclable and self-propulsive micron carbon fiber (CF) immobilizing Fe3O4 nanoparticles with favorable solar-Fenton catalytic activity were successfully prepared by a combined twostep method. In the first step, CF was synthesized from waste paper and subsequently modified by mussel-inspired polydopamine (PDA) with biomimetic adhesion function and highly active functional groups. In the second, well-dispersed Fe3O4 nanoparticles were fabricated and anchored on the surface of the PDA modified CF. The solar-Fenton catalytic performance and reusability for the composites were fully evaluated. The results show the degradation rate of the prepared catalyst for methylene blue (MB) in a free agitating process reached 97.8% after 80 min under simulated Sunlight. After 10 repetitive catalytic cycles, the degradation rate for MB could maintain above 95% meanwhile the magnetic properties of the catalyst remained strong indicating good recovery of the catalyst after the reaction. The possible degradation mechanism of MB is also discussed. It indicates that hydroxyl radicals play an important role in the catalytic degradation reaction, while hole trapping and superoxide radical are beneficial to the enhancement of decolorization efficiency of MB. [ABSTRACT FROM AUTHOR]

By exploiting the hydrophilicity of cellulose filter paper (FP) and the excellent chelating property of chitosan (CH) for Mn2+, we have designed an efficient and retrievable dip catalyst MnO 2 /CH-FP for Fenton-like degradation of methylene blue (MB) over a wide pH range from 2.8 to 11.2. The MnO 2 nanoparticles were uniformly immobilized in the CH-FP matrix by in-situ redox precipitation method where Mn(NO 3) 2 was treated with KMnO 4 at mild conditions. A series of MnO 2 /CH-FP hybrids with different MnO 2 loading were fabricated via varying concentration of Mn(NO 3) 2 solution, and their structure-function relationships were discussed based on detailed characterization. The optimal catalyst 1.0MnO 2 /CH-FP could cooperate with multiple low-concentration dosages of H 2 O 2 to efficiently degrade 95.6% MB in 90 min (50 mg L−1 MB, 1 g L−1 catalyst, 30 mg L−1 H 2 O 2 , pH 7). It is also shown that 1.0MnO 2 /CH-FP could still keep 83.3% degradation efficiency of MB after six cycles. Moreover, the activity of this composite greatly surpassed that of bare MnO 2 for nearly 50%, owing to its larger surface area and more accessible active sites. This method for preparing MnO 2 /CH-FP could effectively avoid the agglomeration of MnO 2 nanoparticles and make the reaction turn on/off almost instantaneously by mere insertion/removal. Image 1 • Nano-MnO 2 was in-situ anchored on the biopolymer by redox precipitation method. • It was an efficient and highly retrievable dip catalyst for Fenton-like degradation. • The hybrid has lager surface area and more accessible active sites than bare MnO 2. • The relationship between MnO 2 loading and degradation efficiency was discussed. • Multiple low-concentration doses of H 2 O 2 could achieve better decolorization. [ABSTRACT FROM AUTHOR]

A flexible paper-structured catalyst (PSC) that can be applied to the anode of a solid oxide fuel cell (SOFC) was examined for its potential to enable direct internal reforming (DIR) operation. The catalytic activity of three types of Ni-loaded PSCs: (a) without the dispersion of support oxide particles in the fiber network (PSC-A), (b) with the dispersion of (Mg,Al)O derived from hydrotalcite (PSC B), and (c) with the dispersion of (Ce,Zr)O 2-δ (PSC C), for dry reforming of CH 4 was evaluated at operating temperatures of 650–800 °C. Among the PSCs, PSC-C exhibited the highest CH 4 conversion with the lowest degradation rate. The electrochemical performance of an electrolyte-supported cell (ESC) was evaluated under the flow of simulated biogas at 750 °C for cases without and with the PSCs on the anode. The application of the PSCs improved the cell performance. In particular, PSC-C had a remarkably positive effect on stabilizing DIRSOFC operation fueled by biogas. • Direct internal reforming (DIR) SOFC fueled by biogas has been investigated. • Paper-structured catalyst (PSC) was examined for the application to DIRSOFC. • Coking-tolerant PSC for dry reforming was developed by the dispersion of (Ce,Zr)O 2-δ. • On-paper synthesis of (Ce,Zr)O 2δ contributed to its higher dispersion. • Performance of DIRSOFC was stabilized by applying the developed PSC on anode. [ABSTRACT FROM AUTHOR]

Re-use of a catalyst is an important task, which is usually achieved by loading it on easily separable supports such as magnetic substrates. However, we demonstrate here the process of easy and fast catalyst separation from a reaction medium by loading it onto an economically feasible and microscopically high surface substrate of filter paper (FP) made up of cellulose microfibers as catalyst support. To achieve the goal, we coated chitosan (CH) on filter paper (CH-FP) to impart a high affinity of the substrate for metal ion absorption. AgNO dissolved in water with a 0.1 M concentration was used as the Ag ion carrier solution, and CH-FP strips with known rectangular dimensions were submerged into it for the metal ion absorption. The metal ion-laden CH-FP strips were dip treated with sodium borohydride (NaBH) aqueous solution to prepare Ag-nanoparticle loaded CH-FP (Ag/CH-FP). X-ray diffraction and energy dispersive X-ray spectroscopy confirmed the formation of the Ag/CH-FP hybrid. Ag/CH-FP morphology was examined through scanning electron microscopy analysis, which showed the presence of Ag nanoparticles attached to the cellulose microfibers. The prepared Ag/CH-FP was employed as a dip catalyst for the degradation of nitroarene compounds of 2-nitophenol (2-NP) and 4-nitrophenol (4-NP) by NaBH. Remarkably, the rate constants for 4-NP and 2-NP were 3.9 × 10 and 1.7 × 10 s, respectively. In addition, we discussed the ease of the catalyst retrievability from the reaction mixture and its re-usability. [ABSTRACT FROM AUTHOR]

Pursuing oxygen evolution reaction (OER) catalysts with high activity and stability is attracting many researchers. Here, we first designed and synthesized a biphasic three-dimensional structured catalyst of nickel–cobalt sulfide NiCo2S4-NiS2/CFP, which is a nickel–cobalt sulfide composite decorated on carbon fiber paper (CFP) by a one-step hydrothermal method. It exhibited an overpotential of about 165 mV at a current density of 10 mA cm−2 and a small Tafel slope of 81.54 mV dec−1. Furthermore, the long-term stability of the NiCo2S4-NiS2/CFP nanocomposite was 90.0% of the initial current density even after 12 h. The excellent catalytic performance of the NiCo2S4-NiS2/CFP nanocomposite can be attributed to several aspects. Firstly, the petal-like morphology of the NiCo2S4-NiS2 nanocomposite exposes more active sites. Secondly, the stability of the composite catalyst is significantly enhanced by its firm anchoring on the CFP. Thirdly, the catalytic performance was significantly improved by the addition of mixed valence of Ni or Co on the {111} plane of spinel NiCo2S4. Finally, the three-dimensional CFP substrate provides an efficient pathway and a stable integrated structure for the transmission of electrons and ions. Our one-step hydrothermal synthesis method provides a simple and economical way to obtain high-performance and robust OER catalysts. [ABSTRACT FROM AUTHOR]

Efficient and durable catalysts for the oxygen evolution reaction (OER) are of great importance for energy storage and conversion devices. However, an objective evaluation and fair comparison of different catalysts remain challenging due to the different catalyst loadings and substrates for OER measurements. In this work, we investigated NiFe layer double hydroxide and commercial Ni/NiO catalysts with different loadings and substrates of glassy carbon (GC), porous nickel foam (NF), and carbon paper (CP). The activity, cycling stability, and potentiostatic stability of the catalysts are compared with respect to the loading and substrate. Catalyst loading exhibits a volcano trend with OER activity, while it has little impact on stability. The 3D substrates NF and CP significantly improved the OER activity of the catalysts compared to GC, especially at higher loadings. The consistent degradation trend of the catalysts confirms the validity of using NF or CP as substrates for the stability test. [ABSTRACT FROM AUTHOR]

Developing high-efficiency electrocatalysts for the hydrogen evolution reaction (HER) is of great importance. In this paper, dendrite-free Ni–Cu catalysts were synthesised via one-step pulse electrodeposition under a weak magnetic field (0.5 T). Regardless of the direction of the magnetic field, the ions were affected by the magnetohydrodynamic (MHD) effect, which greatly promoted the mass transfer and dispersion uniformity, and suppressed the uncontrollable agglomeration by electrodeposition. It was found that the nucleation mechanism changed from progressive nucleation under a 0 T magnetic field to instantaneous nucleation under a 0.5 T magnetic field. Large-scale (325 nm, 0 T) dendrite growth on the single-sided plane was successfully suppressed, and replaced by smaller (90 nm, 0.5 T) and uniformly distributed cluster growth around the carbon paper. In addition, the (111) plane was strengthened by the magnetic field. Electrochemical analysis showed that the Ni–Cu catalysts exposed more surface area and exhibited greatly enhanced catalytic activity, which only needed −57.3 mV to deliver the current density of 10 mA cm−2 with a small Tafel slope of 99.4 mV dec−1 in 1 M KOH. Overall, magneto-electrodeposition, especially under weak magnetic field conditions, provides great promise for the preparation of HER catalysts. [ABSTRACT FROM AUTHOR]

It has been a research goal to develop macroscopic materials with an optimized surface structure to affix silver nanoparticles which could contaminate water and maximize their practical functions. Cellulose paper is a versatile biomass material valued for its abundance, low cost, biocompatibility, and natural composition. Until now, its potential application in water purification has not been adequately explored. In this study, gallic acid-modified silver nanoparticles (GA@AgNPs) were loaded onto commercial cellulose filter paper using a simple lipoic acid modification process (GA@AgNPs-LA-CP). Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) were used to characterize the GA@AgNPs-LA-CP. The catalytic activity of the GA@AgNPs-LA-CP was evaluated by the reduction reaction of methylene blue (MB), Rhodamine B (RhB), and 4-nitrophenol (4-NP) with sodium borohydride (NaBH4). The GA@AgNPs-LA-CP exhibited excellent catalytic activity toward MB, RhB, and 4-NP, taking advantage of its high specific surface area generated by the cellulose fiber network structure. Interestingly, due to the electrostatic interactions between the cationic dyes and the GA@AgNPs, the as-prepared catalytic composite material serves as a better catalyst for MB and RhB, suggesting dual applications of the composite materials for organic wastewater treatment and the removal of harmful dyes. This implies that the immobilization of AgNPs on cellulose papers is an effective method and can be applied to efficient wastewater treatment applications. [ABSTRACT FROM AUTHOR]

• Co doped MoS 2 was decorated on nitrogen-doped carbon fiber/carbon paper (NCFCP) by a solvothermal process. • The lattice spacing of (1 0 0) plane of Co-MoS 2 was slightly narrow than that of MoS 2. • The as-prepared Co-MoS 2 /NCFCP hybrids showed enhanced electrochemical activity for HER. In this paper, Co-doped MoS 2 (Co-MoS 2) with various Co/Mo mole ratio (6%–12%) decorated on nitrogen-doped carbon fiber/carbon paper (NCFCP) (Co-MoS 2 /NCFCP) is fabricated by a solvothermal method as an efficient electrocatalyst for hydrogen evolution reaction (HER). The NCFCP substrate is prepared by electrochemical deposition of polypyrrole on carbon paper followed by heat treatment. The obtained 9% Co-MoS 2 /NCFCP hybrid catalyst exhibits an excellent electrocatalytic HER activity with a low overpotential of 174 mV at 10 mA cm−2, a small Tafel slope of 52 mV dec−1 and long-term stability. Thus, Co-MoS 2 /NCFCP hybrid holds high potential as an efficient earth-abundant electrocatalyst material for HER. [ABSTRACT FROM AUTHOR]

• Co-pyrolysis of polyvinyl chloride (PVC) and paper mill sludge (PMS). • Enhanced production of H 2 and CO by co-pyrolyzing PVC and PMS in CO 2. • Formation of highly graphitic carbon and magnetite on composite during co-pyrolysis. • Generation of OH and SO 4 − radicals that can actively degrade azo dye. • Demonstrated reusability of composite as catalyst for S 2 O 8 2−activation. In this work, polyvinyl chloride (PVC) and paper mill sludge (PMS) were co-pyrolyzed under two environments of N 2 and CO 2. The pyrolysis process was assessed by conducting thermogravimetric analysis (TGA) and monitoring the evolution of gaseous products. The resulting solid composites were characterized using XRD, XPS, BET, and Raman analyzers, and their ability to catalytically activate persulfate (S 2 O 8 2−) was tested by conducting methyl orange (MO) degradation experiments. Co-pyrolysis of PVC and PMS at the same mass ratio (1:1) in CO 2 resulted in the highest production of H 2 and CO (0.36 mol % H 2 at 480 °C & 1.53 mol % CO at 700 °C). The characterization results revealed that the composite consisted of Fe 3 O 4 , highly graphitic carbon, and mesoporous structure. In MO oxidation experiments, the co-pyrolyzed composite actively generated OH and SO 4 − by activating S 2 O 8 2− to achieve complete removal of 5 mg L-1 of MO during 100 min at acidic-neutral pH condition. The composite was also able to complete 3 successive cycles of MO oxidation without deactivation. Consequently, the feasibility of achieving the simultaneous production of energy resources and catalyst via industrial wastes utilization in pyrolytic process was demonstrated. [ABSTRACT FROM AUTHOR]

This work deals with the performance of a microbial fuel cell, focusing on the electrocatalytic activity of selected cathodes constructed by coating nanocomposites over graphite felt under neutral pH in a doublechamber configuration using paper-recycled waste water as a typical electrolyte. Among all cathodes, iron phthalocyanine (FePc) combined multiwalled carbon nanotubes (MWCNT) shows the highest power density (9.34 W/m2) compared to other two catalysts, FePc/Ketjan black (4.68 W/m2) and MWCNT (2.9 W/m2) under similar conditions of using a reference platinum/carbon (Pt/C) loading of 0.5 mg/cm2. The morphology of these catalyst coated electrodes was characterized by scanning electron microscopy. Their electrocatalytic activities were examined using cyclic voltammetry. This work provides an appropriate alternative for cathode catalysts in treatment as well as in electricity production as demonstrated by the high power density of the above catalysts compared to that using precious Pt metal catalyst in microbial fuel cells. [ABSTRACT FROM AUTHOR]

Co(salen) powders were homogeneously scattered over a ceramic fibre network to give a catalyst paper and the Co(salen) paper was tested for the oxidative degradation of a kraft lignin using H2O2 as an oxidant. Due to the structural effect of the interconnected 3D-network, the catalyst paper exhibited a higher performance in the oxidation of kraft lignin with a oil yield of 23.27 % than the original Co(salen) powder with an oil yield of 10.63 %, along with excellent recycling performance. 2,6-Dimethoxyphenol (2.32 mg/kg kraft lignin), vanillin (3.80 mg/kg kraft lignin), and syringaldehyde (2.63 mg/kg kraft lignin) were found to be the main products in the oil obtained. In addition, the structural changes in the kraft lignin were also studied during the process. The phenolic compounds were formed through side chain oxidation together with the oxidative cleavage of α-O-4 linkage. [ABSTRACT FROM AUTHOR]

A novel MnOx-deposited paper-like stainless steel fibers entrapped activated carbon catalyst (Mn-GAC/PSSF) was synthesized by papermaking technology and incipient wetness impregnation (IM) method for methyl ethyl ketone (MEK) combustion, and Mn-deposited granular activated carbon catalyst (Mn-GAC) was prepared simultaneously as a contrast. Characterization of all the samples were carried out by using X-ray diffraction patterns (XRD), N 2 adsorption-desorption, scanning electron microscopy (SEM), H 2 -Temperature programmed reduction (TPR) and X-ray photoelectron spectra (XPS). SEM showed that the Mn oxides on the carbons were relatively well distributed as that on the stainless steel fibers. XPS indicated that the Mn coexisted as Mn3+ and Mn4+. The catalytic activity test for MEK combustion was carried out at atmospheric pressure in a continuous fixed bed stainless steel tube reactor, the results revealed that the Mn-GAC/PSSF catalysts were much more active than Mn-GAC catalyst due to the properties of excellent mass transfer and contacting efficiency offered by PSSF structure, and exhibited high selectivity for complete oxidation of intermediates. Catalyst with higher Mn loading presented higher catalyst activity, the conversion of MEK reached to 90% at 521 K over the 30%-Mn-GAC/PSSF catalysts, while it was 566 K and 530 K over the 10%-Mn-GAC/PSSF catalyst and 20%-Mn-GAC catalyst, respectively. • Microfibrous entrapped activated carbon catalyst (Mn-GAC/PSSF) were prepared. • The Mn-GAC/PSSF catalyst presents efficient activity for MEK oxidation. • Catalytic efficiency of Mn-GAC/PSSF is superior to granular Mn-GAC. [ABSTRACT FROM AUTHOR]

A paper-structured catalyst (PSC) for biogas reforming was prepared with the aim of improving coking tolerance. During the paper-making process using inorganic fibers, Ni-loaded (Ce,Zr)O 2–δ particles were synthesized via co-precipitation and subsequent chemical reduction (on-paper synthesis). The effects of the CeO 2 /ZrO 2 weight ratio during preparation and the Ni loading amount on the catalytic activity for dry reforming of CH 4 were investigated at 750 °C. A Ni loading of 6 wt% with CeO 2 /ZrO 2 ≥ 1 led to stable CH 4 conversion of 85% without coking under a gas hourly space velocity of 3800 h −1 . The oxygen storage capacity of the (Ce,Zr)O 2–δ particles dispersed in the inorganic fiber network may contribute to the oxidation of carbonaceous species deposited on the catalyst surface. [ABSTRACT FROM AUTHOR]

In this study, a piece of filter paper with good flexibility and hygroscopicity was used to support catalysts after a pencil drawing process. A layer of thin Ni film was deposited on the surface of the conductive graphite layer using an electrochemical method at a negative potential. Pd nanoparticles with high electrocatalytic activity for NaBH4 oxidation were introduced by immersing the Ni film-graphite-filter paper (NGF) in PdCl2 solution to obtain a Pd-NGF (PNGF) electrode. The morphology and phase structure of PNGF were characterized using scanning electron microscopy (SEM) equipped with an energy dispersive X-ray spectrometer (EDS), transmission electron microscopy (TEM) and an X-ray diffractometer (XRD). The PNGF electrode was used as the anode in direct borohydride fuel cells (DBFCs), and the electrochemical properties for NaBH4 oxidation were determined by cyclic voltammetry (CV), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS). The oxidation current density reaches 550 mA cm−2 at −0.4 V when the electrolyte contains 2 mol dm−3 NaOH and 0.10 mol dm−3 NaBH4. [ABSTRACT FROM AUTHOR]

The catalytic combustion of diesel soot is addressed with flexible and structured "paper catalysts". Two different series of catalysts were prepared either by drip impregnation or by a spray method to deposit a mixture of Co, Ba, and K or a mixture of Co and Ce onto SiO2-Al2O3 ceramic paper matrixes. In every case, CeO2 nanoparticles were added to bind the ceramic fibers. SEM images showed that the impregnation method generated catalytic particles concentrated as large chunks (> 10 μm), mainly at ceramic fiber crossings, whereas the spray method produced smaller catalytic particles (< 1 μm) well distributed throughout the ceramic paper. Besides, Co-Ba-K particles appeared better dispersed on the surface of ceramic fibers than Co-Ce due to the presence of K. Additionally, FTIR spectra showed the formation of O22− and O2− species associated with CeO2 (binder) on the samples containing potassium which gave the Co-Ba-K-ceramic paper good catalytic properties, thus making the Co-Ba-K drop impregnated the best catalyst both considering activity and stability. Successive temperature programmed oxidation (TPO) runs up to 700 °C caused the formation of cobalt silicates in the catalytic ceramic paper prepared by the spray method, as indicated by TPR. The formation of these species was probably favored by the smaller size of cobalt particulates and their higher dispersion in the catalysts prepared by the spray method. This provoked the partial loss of the redox properties of Co3O4. TPR experiments also indicated the formation of BaCoO3 in Ba-containing ceramic paper, which could help in maintaining the catalyst activity after several TPO runs through the capacity of this mixed perovskite-type oxide to trap and release NOx. [ABSTRACT FROM AUTHOR]

It is a great challenge to synthesize efficient electrocatalysts for overall water splitting, especially non‐noble metal catalysts. Herein, one‐dimensional polycrystalline nanoneedles composed of CoO−Co9S8 nano heterostructures, in situ grown on carbon fiber paper are prepared for efficient overall water electrolysis. Due to strong electronic coupling, charge densities of Co2+/Co3+ in Co9S8 and Co2+ in CoO are favorably modified at the interface of CoO and Co9S8, resulting in optimized reaction intermediates absorption and greatly enhanced bifunctional HER/OER activities. CoO−Co9S8/CFP delivers a current density of 10 mA cm−2 in alkaline electrolyte at overpotentials of 184 mV and 270 mV for HER and OER, respectively. When used as electrocatalyst for overall water splitting, it needs a low cell potential of 1.66 V to realize water electrolysis at 10 mA cm−2. This work provides a new strategy to tune the electronic structures of transitional metal active sites via constructing nano heterostructures for efficient water electrolysis. [ABSTRACT FROM AUTHOR]

Fe, N co-doped carbon electrocatalyst is one of the most attractive alternatives to Pt/C catalysts due to its high catalytic activity, excellent stability and low cost. However, obtaining stable and efficient Fe, N co-doped carbon oxygen reduction reaction (ORR) catalysts based on simple processes is still a challenge. Herein, Fe, N co-doped porous carbon (Fe–N–C) with an open macroporous frame structure is prepared by using inorganic molten salts (FeCl3·6H2O and ZnCl2) and ethylenediaminetetraacetic acid as the template and nitrogen-containing carbon precursor, respectively. The open pore structure of the Fe–N–C material precisely tailored with the inorganic molten salt template exhibits high specific surface area (676.5 m2 g−1) and appropriate pore size, which can promote oxygen adsorption and expand the oxygen reduction interface, resulting in the acceleration of the electron/charge transfer processes and an improved electrocatalytic performance. The optimized Fe3–N–C-800 electrocatalyst exhibits good catalytic activity for ORR, such as high onset potential of 0.998 V and half wave potential of 0.84 V in alkaline media, as well as high stability and methanol tolerance. Furthermore, a novel Zn–air battery assembled with carbon paper containing Fe3–N–C-800 electrocatalyst as air cathode shows high open-circuit voltage (1.485 V), high specific capacity (870 mA h g−1 at 10 mA cm−2), excellent reversibility and stability. The proposed synthetic strategy provides new opportunities to design and construct carbon frame materials with the desired open macroporous structure to improve their electrocatalytic performance. [ABSTRACT FROM AUTHOR]

In this study, sludge-derived Fenton-like catalysts, namely potentially low cost, were successfully synthesized through a unique and original method, which was used to oxidative degradate Rhodamine B (RhB) as heterogeneous Fenton-like Fe/C catalysts. Two types of sludge sources were used as sludge-derived support carbon: paper mill sludge and municipal wastewater treatment sludge. This unique preparation method converted pyrolyzed sludge into a porous carbon-based carrier material by chemical activation and then used an iron loading impregnation method to synthesize the Fenton-like Fe/C catalyst. The prepared two types of catalysts including paper mill sludge-derived char-supported iron catalyst and municipal sewage sludge-derived char-supported iron catalyst were characterized in terms of Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy and N2-adsorption/desorption. Compared with sludge-derived Fe/C catalyst without activation, both the PMSC-Fe and the MSSC-Fe catalyst exhibited much better catalytic performance in degrading RhB. Both PMSC-Fe and MSSC-Fe exhibited excellent catalytic stability and almost seldom Fe-ion leaching. A correlation could be found between surface area and RhB degradation, suggesting that surface area of the catalyst is an important factor for the catalytic performance. Two different sources of sludge also showed discrepancy in catalytic performance of RhB degradation, which is perhaps due to the different properties of the initial sewage sludge. The catalyst of PMSC-Fe and MSSC-Fe both has an excellent long-term stability. Possible degradation mechanism of RhB induced by sludge-derived Fe-C/H2O2 system is proposed. [ABSTRACT FROM AUTHOR]

[Display omitted] • Immobilization of CuO on paper matrices by an ultrafast (5 min) microwave method. • CuO immobilized paper catalyzes the conversion of CO 2 into cyclic carbonates. • Excellent recyclability of the catalyst (98 % efficiency even after 7 cycles). • Environmental catalyst catalyzes notorious CO 2 to products of industrial importance. Paper matrices immobilized with CuO nanoflakes (width 50−100 nm and length upto 200 nm) by an ultrafast (5 min) microwave assisted method have been used as catalyst for the conversion of CO 2 and epoxides into cyclic carbonates with almost 100 % yield in 20 h at a comparatively low CO 2 pressure of 4 bar. Additionally, some amount of polycarbonate is also formed. The moderate TON of 121 and excellent recyclability performance (98 % retention of the catalytic activity) even after seven catalytic cycles along with the non-detectable leaching of the CuO from the paper matrices and ease of separation of the catalyst, made the CuO immobilized paper matrices a superior catalyst. The cellulose matrices not only act as a support to immobilize the CuO nanoparticles but also acts as a co-catalyst due to the presence of ample amount of hydroxyl groups in this biodegradable natural polymer. The synergy of cellulose and CuO in the immobilized paper matrices for the formation of the products can be seen as only 7 or 40 % conversion were estimated when only paper matrices or CuO was used as the catalysts, respectively. Moreover, as substrate the paper matrices has shown great potential as the destruction and re-fabrication for five consecutive cycles could hold more than 95 % of the immobilized CuO in the paper matrices. [ABSTRACT FROM AUTHOR]

The Fe-N-C nanofibers (NFs) exhibit excellent electro-catalytic activity for oxygen reduction reaction (ORR), which is essential for energy conversion system. Compared with the traditional ink-based electrode, we synthesized the structured Fe-N-C ANFs/CP (activated NFs derived from polypyrrole(PPy) doped with iron atoms in situ grown on carbon paper) by electrochemical polymerization. Herein, we investigate the effect of the iron concentration on the electro-catalytic activity for ORR, revealing that the as-prepared 0.05-Fe-N-C ANFs exhibit superior electro-catalytic activity than 0.01-Fe-N-C ANFs, 0.03-Fe-N-C ANFs as well as 0.10-Fe-N-C ANFs and excellent durability in alkaline solution. It is shown that the better electro-catalytic activity of 0.05-Fe-N-C ANFs for ORR could be ascribing to the fluffy fibrous structure, higher Fe-Nx concentration, and well-dispersed catalytic active sites. [ABSTRACT FROM AUTHOR]