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Electrochemical reduction reactions, as cathodic processes in many energy‐related devices, significantly impact the overall efficiency determined mainly by the performance of electrocatalysts. Metal–organic frameworks (MOFs) derived carbon‐supported metal materials have become one of star electrocatalysts due to their tunable structure and composition through ligand design and metal screening. However, for different electroreduction reactions, the required active metal species vary in phase component, electronic state, and catalytic center configuration, hence requiring effective customization. From this perspective, this review comprehensively analyzes the structural design principles, metal loading strategies, practical electroreduction performance, and complex catalytic mechanisms, thereby providing insights and guidance for the future rational design of such electroreduction catalysts. [ABSTRACT FROM AUTHOR]

We prepared a simple, one-step synthesis of Pt-M (M = Co, Cu & Fe)/C supported on Vulcan-XC-72 carbon using the polyol reduction method. The morphology, structure and elemental composition of the prepared catalysts were confirmed by transmission electron microscopy (TEM), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX). Electrochemical characterization including electrochemical impedance, cyclic voltammetry and chronoamperometry were studied to compare the electrochemical activity of the as-prepared catalyst with standard 20 wt % Pt/C. From transmission electron microscopy studies, the estimated average particle size for PtFe/C, PtCo/C and PtCu/C were 16, 12 and 10 nm respectively. In cyclic voltammetry studies, the PtFe/C catalyst exhibited the maximum current density for electrooxidation of methanol (14.88 mA cm−2), compared to PtCu/C (9.96 mA cm−2), PtCo/C (4.66 mA cm−2) and Pt/C (2.34 mA cm−2). Also, the negative sweep onset potential and greater If/Ib ratio verified the enhanced activity of the PtFe/C catalyst. The stability of the catalyst was studied using chronoamperometric methods, which reveals the slow decay of the prepared catalyst and higher current density for initial and final time intervals. Impedance studies confirm that the PtFe/C catalyst exhibits the smallest semicircle, suggesting a significantly higher electrooxidation rate in comparison to the other catalysts. The electrocatalytic activity of the prepared catalyst follows the order: PtFe/C > PtCu/C > PtCo/C > Pt/C.

Electrochemical dechlorination reaction (EDR) is a promising, environmentally friendly, and economically profitable technology for treating chlorinated organic pollutants. For efficient environmental protection, electrocatalysts with high stability and low cost are of extremely significance to the development of EDR technology. Carbon-based materials have aroused broad interest as electrocatalysts for many electrochemical reactions due to their characteristics including large specific surface area, controllable structure, good conductivity, and chemical stability. For EDR, the carbon-based materials also show many unique superiorities, like strong adsorption capacity to chlorinated organic compounds (COCs), excellent catalytic activity and stability, and environmental compatibility. This review starts with a detailed summary on the mechanisms of electrochemical dechlorination (direct and indirect electron transfer pathway) and factors affecting the effectiveness of EDR. Then the paper comprehensively overviews the current progresses of carbon-based materials for EDR of COCs, following their two major application scenarios, i.e., directly as electrocatalysts and as advanced supports for other catalysts. Moreover, the formation of different active sites in carbon-based electrocatalysts and their EDR activities are analyzed. Finally, the current challenges and perspectives in this field are discussed. This review will provide an in-depth understanding for the design of advanced carbon-based materials and promote the development of EDR technology. [ABSTRACT FROM AUTHOR]

The lifespan of proton‐exchange membrane fuel cells heavily relies on the durability of the carbon support of cathode catalysts. However, commercial carbon supports like ketjenblack (KB) and Vulcan carbon (VC) face the challenge of balancing porosity, surface area, and electrochemical stability. To address this issue, a 3D porous wrinkled graphitic carbon (PWGC) is designed and synthesized using a catalyst‐free, plasma‐enhanced chemical vapor deposition approach. The resulting PWGC possesses a hierarchically porous structure with a high surface area, a high degree of graphitization, and exceptional corrosion resistance. As a result, the Pt/PWGC catalysts with the use of PWGC as the carbon support demonstrate superior high potential stability compared to those made with KB and VC as the carbon support. Additionally, a sacrificial layer strategy is introduced to further reduce PWGC corrosion, resulting in Pt@C/PWGC catalysts that show significantly improved durability in membrane electrode assembly tests. After 5K voltage cycles from 1.0 to 1.5 V, the retention of electrochemically active surface area approaches 56.8%, surpassing the 23.6% retention of commercial Pt/C catalysts tested under the same conditions. [ABSTRACT FROM AUTHOR]

When early transition metal complexes are molecularly grafted onto catalyst supports, well‐defined, surface‐bound species are created, which are highly active and selective single‐site heterogeneous catalysts (SSHCs) for diverse chemical transformations. In this minireview, we analyze and summarize a less conventional type of SSHC in which molybdenum dioxo species are grafted onto unusual carbon‐unsaturated scaffolds, such as activated carbon, reduced graphene oxide, and carbon nanohorns. The choice of earth‐abundant, low‐toxicity, versatile metal constituents, and various carbon supports illustrates "catalyst by design" principles and yields insights into new catalytic systems of both academic and technological interest. Here, we summarize experimental and computational investigations of the bonding, electronic structure, reaction scope, and mechanistic pathways of these unusual catalysts. [ABSTRACT FROM AUTHOR]

We have studied Cu–Zn and Cu–Ni containing catalysts on carbon supports based on IR-pyrolyzed chitosan and detonation nanodiamond (DND) and assessed their activity for the methanol steam reforming process. All of the catalysts have demonstrated rather high activity for this process and good stability over 30 h of continuous operation. The DND-based catalysts have been shown to have better performance, which seems to be due to their larger surface area and the nature of the functional groups on their surface. The activity of the bimetallic catalysts and the nature of the supports have been shown to be interrelated. [ABSTRACT FROM AUTHOR]

Multiwalled carbon nanotubes and Vulcan carbon were functionalized with a 30 %v/v hydrogen peroxide solution and employed as supports for Pt and PtSn catalysts prepared by the polyol method. PtSn catalysts with a Pt loading of 20 wt.% and a Pt : Sn atomic ratio equal to 3 : 1 were evaluated in the ethanol electrooxidation reaction. The effects of the oxidizing treatment on the surface area and the surface chemical nature were analyzed through N2 adsorption, isoelectric point, and temperature‐programmed desorption measurements. Results showed that the H2O2 treatment affects the surface area of the carbons to a great extent. Characterization results indicated that the performance of the electrocatalysts strongly depends both on the presence of Sn and on the support functionalization. PtSn/CNT−H2O2 electrocatalyst displays a high electrochemical surface area and enhanced catalytic activity for ethanol oxidation in comparison to other catalysts in the present study. [ABSTRACT FROM AUTHOR]

In recent years, there has been notable progress in developing advanced catalyst materials and improving the performance of Pt-based catalysts for the oxygen reduction reaction (ORR). ORR is pivotal for achieving high energy conversion efficiency in fuel cells and metal-air batteries. Despite extensive research, balancing the activity and stability of electrocatalysts remains challenging. Due to the high cost and limited availability of Pt, there's a focus on developing Pt alloys, hybrid catalysts, and nanostructured materials with enhanced catalytic activity and utilization using cost-effective methods. Hybridizing multiple active components with Pt shows promise for achieving synergistic effects and meeting high-performance targets set by the U.S. Department of Energy for 2025. This review aims to present recent advances and assess the significance of supported and support-free Pt-based electrocatalysts for ORR. It focuses on carbon, inorganic, and hybrid support materials, as well as support-free metal nanostructures, highlighting their key features and catalytic potential. This offers valuable insights into developing novel Pt-based hybrid electrocatalysts for superior ORR performance in energy conversion and storage applications. [Display omitted] • Assessing significance of supported & support-free Pt-based electrocatalysts for ORR. • Synergistic Pt hybridization overcomes material limitations for efficient electrocatalysis. • Insights on Pt-based hybrid electrocatalysts for superior ORR in energy conversion and storage. [ABSTRACT FROM AUTHOR]

To enhance the performance of Ru in hydrogen evolution reaction (HER), the design and fabrication of catalytic supports become one of the critical research topics. Carbon supports possessing the excellent conductivity and remarkable cost advantage have become one of the primary choices in fabrications of composite catalysts. In our present studies, the NHPC (N-doped hierarchical porous carbon) supports are fabricated by the carbonizations of soluble starch, ammonium citrate and sodium bicarbonate, and the Ru/NHPC catalysts are successfully prepared by the reactions of RuCl3·3H2O with NaBH4 and NHPC in the ultrasonic treatment. As a result, it is found that Ru goodly dispersed on the surfaces of NHPC in nano sizes, and the Ru/NHPC catalysts manifest the fabulous HER performance. For instance, the overpotential of 11.2 %Ru/NHPC (the loading of RuCl3·3H2O is 0.05 g) is 33 mV at a current density of 10 mA cm−2, which is remarkably lower than 48 mV of glassy carbon electrode (20 %Pt/C) in alkaline medium (1 M (mol L−1) KOH). The Tafel slope of 11.2 %Ru/NHPC is 36 mV dec−1 at 10 mA cm−2 in the same conditions. Although the 11.2 %Ru/NHPC is in the acidic medium (0.5 M H2SO4), it also displays the routine HER performance. In short, this present study provides a useful approach to facilitate the application of Ru as a hydrogen evolution catalyst.

Magnetic hyperthermia (MH) shows great potential in clinical applications because of its very localized action and minimal side effects. Because of their high saturation magnetization values, reduced forms of iron are promising candidates for MH. However, they must be protected in order to overcome their toxicity and instability (i. e., oxidation) under biological conditions. In this work, a novel methodology for the protection of iron nanoparticles through confinement within graphitic carbon layers after thermal treatment of preformed nanoparticles supported on carbon is reported. We demonstrate that the size and composition of the nascent confined iron nanoparticles, as well as the thickness of their protective carbon layer can be controlled by selecting the nature of the carbon support. Our findings reveal that a higher nanoparticle–carbon interaction, mediated by the presence of oxygen‐containing groups, induces the formation of small and well‐protected α‐Fe‐based nanoparticles that exhibit promising results towards MH based on their enhanced specific absorption rate values. [ABSTRACT FROM AUTHOR]

Functionalization of carbon supports with heteroatom dopants is now widely regarded as a promising route for stabilizing and strengthening the interactions between the support and metal catalysts. Tuning the type and density of heteroatom dopants allows for the tailoring of nanoscale catalyst–support interactions; however, an understanding of these phenomena has not yet been fully realized because of the complexity of the system. In this work, computational modeling, materials synthesis, and advanced nanomaterial characterization are used to systematically investigate the intriguing effect of the two most common nitrogen functionalities in the carbon-based supports on the interactions with selected transition metals toward realizing catalytic applications. Specifically, this study utilized density functional theory to evaluate adsorption energies and modes of adsorption for 12 metals located in groups 8–11 and periods 4–6 with pyridinic and graphitic N defects. Based on these results, further electronic structure investigation of the period 4 metals was conducted to elucidate periodic group trends. Experimental work included synthesis and nanomaterial characterization of a subset of materials featuring three metals each supported on two types of N-doped carbon supports and undoped graphene. Characterization of nanomaterials with scanning transmission electron microscopy and energy-dispersive X-ray spectroscopy confirmed that N functionalities enhanced the interactions with the selected transition metals when compared to the undoped support and demonstrated that the nature of the defect influences these interactions. Both computations and experiments agreed that Fe and Co are biased toward the graphitic sites over pyridinic sites, while Ni has an affinity to both defects without a statistically significant preference. This work established a correlation between computational and experimental work and a framework that can be expanded to other metals and alternative dopants beyond nitrogen in tailoring nanoscale catalyst–support interactions for a breadth of catalytic applications. [ABSTRACT FROM AUTHOR]

Summary: Highly stable and cost‐effective electrocatalysts are of importance in regulating energy conversion efficiency and commercial feasibility of direct methanol fuel cells (DMFCs). So far, integrating transition metals into Pt‐based catalysts to enhance their catalytic performances for methanol electro‐oxidation reaction (MOR) at the anode of DMFCs has received significant interest. This study witnessed the first time of depositing Pt3Co1 alloy nanoparticles (NPs) on robust Ti0.9Ir0.1O2 supports utilizing a modified reduction method that used NaBH4 as a reducing agent in the absence of surfactants or stabilizers. This novel combination not only reduces the usage of costly and easily‐deactivated Pt but also significantly improves catalytic activity and poisoning tolerance for MOR. Regarding electrocatalytic performance, the onset potential and the mass activity of the Pt3Co1/Ti0.9Ir0.1O2 catalyst are ~0.1 V vs NHE and 316.16 mA/mgPt, respectively, which are 4.5‐fold lower and 1.5‐fold higher than the corresponding figures for the commercial Pt/C (E‐TEK) catalyst, ~0.45 vs NHE and 206.83 mA/mgPt, indicating superior catalytic activity and CO‐tolerance of the former over the latter. Furthermore, the superior anti‐poisoning ability and stability of the Pt3Co1/Ti0.9Ir0.1O2 catalyst are demonstrated by its 2.2‐fold higher If/Ib ratio in MOR and lower degradation rate in the 60‐min chronoamperometry (CA) and 3000‐cycle scanning tests than the Pt/C counterpart. These enhancements could be abscribed to synergistic influence between the Pt‐Co alloy NPs and the robust Ti0.9Ir0.1O2 support. The addition of Co into the catalyst to promote removal of Pt‐poisoning species as well as the use of highly corrosion‐resistant Ir‐doped TiO2 as a catalyst support play a decisive role in boosting electrochemical behaviors of the Pt3Co1/ Ti0.9Ir0.1O2 catalyst. Generally, the success of this work in synthesizing high‐performance Pt3Co1/Ti0.9Ir0.1O2 catalyst could serve as groundwork for further development of TiO2‐based material supported bimetallic catalysts for applications in the electrochemical catalysis field. [ABSTRACT FROM AUTHOR]

Hydrothermal carbonization of lignin was used to prepare a precursor of a carbon-containing support to obtain supported iron-containing catalysts for the hydrogenation of carbon monoxide. In the paper, the possibility of forming a carbon support prone to the deposition of metal ions was investigated. Deep structural transformations occurring in the polymer matrix of lignin were demonstrated by FTIR spectroscopy. The thermal stability of the support material was determined by thermal analysis in the region up to 400 °C. The formation of magnetite nanoparticles with a size of about 7-8 nm at the stage of preliminary calcination of the metal-carbon system was shown by X-ray diffraction analysis (XRD). It was found that the resulting systems have high activity comparable to the activity of the system based on activated carbon: the conversion of carbon monoxide reached 98%, the yield of C5+ hydrocarbons reached 72 g/m3. [ABSTRACT FROM AUTHOR]

Hydrothermal carbonization of lignin was used to prepare a precursor of a carbon-containing support to obtain supported iron-containing catalysts for the hydrogenation of carbon monoxide. In the paper, the possibility of forming a carbon support prone to the deposition of metal ions was investigated. Deep structural transformations occurring in the polymer matrix of lignin were demonstrated by FTIR spectroscopy. The thermal stability of the support material was determined by thermal analysis in the region up to 400 °C. The formation of magnetite nanoparticles with a size of about 7‒8 nm at the stage of preliminary calcination of the metal-carbon system was shown by X-ray diffraction analysis (XRD). It was found that the resulting systems have high activity comparable to the activity of the system based on activated carbon: the conversion of carbon monoxide reached 98%, the yield of C5+ hydrocarbons reached 72 g/m3.

Direct methanol fuel cells (DMFCs) have been the focus of future research because of their simple structure, abundant fuel sources, high energy conversion efficiency and low cost. Among the components in DMFC, the activity and stability of the cathode catalyst is the key to the performance and lifetime of the DMFCs. Oxygen reduction reaction (ORR) is an important electrode reaction on DMFC cathode. It is known that Pt is widely used in the fabrication of ORR catalysts, but the limited earth storage of Pt and its high price limit the use of Pt-based commercial catalysts in DMFCs. To overcome these problems, advances have been made on new low Pt-based catalysts and Pt-free catalysts in recent years. In this article, the development of novel ORR catalysts and the carbon supports is reviewed and discussed.

Catalytic conversion of biomass and waste into chemicals and fuels is gaining interest to reach a circular economy. Here, we review carbon-based and carbon-supported nanocatalysts for biomass conversion with focus on catalyst types and synthesis, optimization, mechanisms and three-dimension catalytic structures. Catalystic materials include amorphous carbon, graphene, graphene oxide, carbon nanotubes and carbon nanofibers. [ABSTRACT FROM AUTHOR]

Graphite carbons have been widely used as catalyst support due to their low‐cost, tunable porous structure, high electrical conductivity, and good resistance to harsh conditions. To date, various defect engineerings have been adopted to enhance the cohesion between graphite carbons and metallic nanocatalysts. Nevertheless, the modification of carbon basal plane has been less explored. In this work, a dual modification strategy is developed to achieve novel carbon support (denoted as NCf) incorporating both C60 units and trace N‐defects. Benefiting from the dual anchoring modes (Ru–C and Ru–N–C), ultrafine ruthenium (Ru) nanoclusters (average size: 2.26 ± 0.38 nm) can be well‐dispersed and robustly anchored on the NCf support. The optimal Ru0.013@NCf catalyst exhibits decent catalytic activities and long‐term stabilities toward both alkaline hydrogen evolution reaction (HER) and aromatic nitroreduction (ANR), outperforming the individually modified counterparts. Computational studies suggest that introducing both C60 and N‐defects into carbon support leads to electron‐deficient Ru nanocluster, which is critical for not only HER but also ANR. This work thus provides a new guideline for rational design of advanced carbon supported nanocatalysts for multipurpose applications. [ABSTRACT FROM AUTHOR]

The use of carbon-based materials as catalyst supports for Fischer–Tropsch synthesis (FTS) is thoroughly reviewed. The main factors to consider when using a carbonaceous catalyst support for FTS are first discussed. Then, the most relevant and recent literature on the topic from the last 2 decades is reviewed, classifying the different examples according to the carbon structure and shape. Some aspects such as the carbon textural properties, carbon support modification (functionalization and doping), catalyst preparation methods, metal particle size and location, catalyst stability and reducibility, the use of promoters, and the catalyst performance for FTS are summarized and discussed. Finally, the main conclusions, advantages, limitations, and perspectives of using carbon catalyst supports for FTS are outlined.

The development of highly efficient Pt-based nanocatalysts is important for the commercialization of direct ethanol fuel cells (DEFCs) but remains challenging to achieve. Here in, we developed an ingenious strategy to significantly improve the electrocatalytic property of Pt-based catalyst towards ethanol oxidation reactions (EOR) in acid medium by doping tungsten. In this study carbon (Vulcan XC-72R, Ketjen black, carbon nanotubes) supported Pt-surface-enriched platinum–tungsten bimetallic nanoparticles (W@Pt/C, W@Pt/KJ, W@Pt/CNT) were prepared using the etching effect of galvanic replacement on amorphous tungsten nanoparticles. Additionally, no surfactant is used in the preparation of the catalysts. The catalysts were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and electrochemical methods. From the results, we can conclude that W@Pt nanoparticles were uniformly loaded on each carbon support. Finally, when compared with JM Pt/C, the catalytic activity of W@Pt/C was increased by 30% and the current density retained by W@Pt/C was 1.6 times that of the commercial catalyst (123 mA mgPt−1). At the end of the 3600 s reaction, W@Pt/C retained a current density of 198 mA mg−1 which is 1.6 times that of commercial catalyst JM Pt/C (123 mA mg−1). Also, W@Pt/KJ retained a current density of 176 mA mg−1 which is 1.4 times that of JM Pt/C. Furthermore, the metal oxides (WOX) in the catalyst can easily adsorb -OH species which can transform COads poisoning species to CO2, thus promoting the catalytic activity and stability toward EORs. [ABSTRACT FROM AUTHOR]

• Gold (1 wt.%) was loaded on several carbon materials by two different methods. • Activated carbon, carbon xerogel, microdiamonds, nanodiamonds and graphite were used. • Materials were used for the microwave-assisted solvent-free phenylethanol oxidation. • The highest acetophenone yield (99.9%) was obtained for Au loaded on microdiamonds. • This catalyst was able to maintain higher activity up to several recyclability cycles. Gold (1 wt.%) was loaded on several carbon materials, namely, polymer based carbon xerogel, activated carbon, microdiamonds, nanodiamonds, graphite and silicon carbide by double impregnation and sol immobilisation. The obtained catalysts were characterised by N 2 adsorption at -196 ºC, high-resolution transmission electron microscopy, high-angle annular dark-field imaging (Z-contrast), temperature programmed desorption, atomic absorption spectroscopy and X-ray photoelectron spectroscopy. The obtained materials were tested on the microwave-assisted solvent-free oxidation of 1-phenylethanol by tert -butyl hydroperoxide (TBHP) to produce acetophenone. The results showed that the catalytic activity was influenced by several factors, namely, the nature of the support, reaction time and temperature, amount of catalyst, presence of additives, among others. The best values for acetophenone yield (99.9%) were obtained with Au deposited on microdiamonds by the colloidal method. Catalyst recyclability was tested up to six consecutive cycles at the optimized conditions for each catalyst, and it was found that Au on microdiamonds, prepared by the colloidal method, also maintained higher activity after several reaction cycles as compared to the other carbon supports. [ABSTRACT FROM AUTHOR]

Dual metal FeCo has great potential as Pt-free catalyst in various applications, such as cathodic catalyst for fuel cells, in order to reduce the cost significantly and make fuel cell commercialization, viable. In this study, dual metal FeCo catalyst supported on carbon Vulcan XC-72, carbon nanotubes (CNT), and reduced graphene oxide (rGO) were successfully prepared via facile co-precipitation method with varying weight ratios of Fe and Co. The structure of the as-prepared catalysts was characterized by powder X-ray diffraction (XRD), scanning electron micrographs (SEM), and X-ray photoelectron spectroscopy (XPS). The XPS analysis revealed that CoFe2O4 were present on the catalyst particle surface with different Fe to Co ratio. The emergence of the new peak at 530.5 eV is assigned to the deposition of CoFe2O4, which is enabled via Fe-O-Co bonds. The FeCo/rGO catalyst with weight ratio of 2:1 exhibited the optimum performance for oxygen reduction reaction (ORR), with reduction peak of 0.163 mA cm-2 at 0.385 V vs. Ag/AgCl in an acidic media. The experimental result suggested that the dual metal FeCo catalyst display favourable electrocatalytic activity towards ORR and appears to be a promising cathodic electrocatalyst for an acidic fuel cell. [ABSTRACT FROM AUTHOR]

The Fischer‐Tropsch reaction transforms syngas into high added value products, among which liquid fuels. Numerous parameters determine catalytic activity and selectivity towards the most desired hydrocarbons. The performances of cobalt‐based catalysts used in the reaction are known to depend critically on Co particle size and crystallographic phase. Here, we present a comparative study of Co‐based catalysts supported on three carbon supports: multi‐wall carbon nanotubes, carbon nanofibers and a fibrous material. Our results show that, while the selectivity towards C5+ follows the expected tendency with respect to Co particle size, this is not the case for the TOF. These results can be rationalized considering that the amount of H2 uptake on each catalyst increases with oxygen and defect concentration on the support. The catalyst on the support presenting many edges and oxygen surface groups, necessary for H2 spillover, presents the highest activity. Furthermore, the hydrogen spillover contributes to the enhancement of olefin hydrogenation and methane production. [ABSTRACT FROM AUTHOR]

Fischer-Tropsch synthesis (FTS) attracts great interest as a sustainable route for production of sustainable transportation fuels. Catalyst design and operational conditions tune the selectivity of FTS to liquid fuels, which can be predicted with machine learning models (ML). Herein, a comprehensive dataset including 27 key input features related to the catalyst structure (with the focus on carbon supports), preparation, activation, and FTS operating conditions were investigated to predict the CO conversion and C 5+ selectivity using three ML algorithms. Feature engineering and selection were implemented to identify the significant catalyst formulation descriptors. Principal component analysis was used to explore the information space and decrease the dimension of the dataset before ML prediction. In addition to the well-known effects of the operational conditions on FTS, roles of physico-chemical properties of the carbon materials were also extensively analyzed. Random forest (RF) including 4 principal components, indicated the highest accuracy for prediction of the CO conversion and C 5+ selectivity with R2 of 0.91 and 0.97, respectively. The proposed framework can provide a reliable strategy in designing efficient carbon supported catalysts for FTS and guide experiments by identifying the key descriptors in the catalyst formulation and operating conditions to enhance the selectivity of liquid fuels. [Display omitted] • A machine learning framework for CO hydrogenation to clean liquid fuels with the focus on carbon supports was developed. • Catalyst characteristics, preparation, activation, and operating conditions were compiled in the dataset. • Principal component analysis was conducted to evaluate the information space before machine learning modeling. • Random forest led to the highest prediction accuracy of catalyst selectivity to C 5+ with R2 = 0.97. • According to the SHAP theory, catalyst characteristics were identified as the most significant features. [ABSTRACT FROM AUTHOR]

Supporting gold nanoparticles have shown to be extremely active for many industrially important reactions, including oxidations. Two representative examples are the oxidation of alcohols and alkanes, that are substrates of industrial interest, but whose oxidation is still challenging. This review deals with these reactions, giving an insight of the first studies performed by gold based catalysts in these reactions and the most recent developments in the field.

Catalytic layers on the surface of Toray Carbon Fiber Paper TGP-H-060 T and AVCarb® Carbon Fiber Paper P50 carbon carriers are formed by the ion-beam-assisted deposition of platinum and rare-earth-metal gadolinium (as an activating additive) in order to obtain electrocatalysts for the direct oxidation of ethanol and methanol for fuel cells with a polymer membrane electrolyte. The formation of the layers is carried out in the ion-beam-assisted deposition mode, in which metal deposition and mixing of the deposited layer with the substrate surface with accelerated (U = 5 kV) ions of the same metal are carried out, respectively, from the neutral fraction of the vapor and plasma of a vacuum pulsed arc discharge. The microstructure and composition of the obtained surface layers are studied using scanning electron microscopy, electron probe X‑ray spectral microanalysis, X-ray fluorescence analysis, and Rutherford backscattering spectrometry. As a result of the ionic mixing of all components, multicomponent layers containing atoms of precipitated metals and substrate elements, as well as oxygen impurities, are obtained. [ABSTRACT FROM AUTHOR]

The Pd/C catalysts are widely used in synthesis of fine chemicals in industry, but their production suffers from a complicated two‐step process involving impregnation and reduction, and requires large amounts of solvents and reductant, which would lead to a series of issues such as time consumption, resource waste and environmental pollution. Herein, ultra‐small Pd nanoparticles uniformly anchored on carbon nanotubes (Pd/CNTs) were synthesized by using a one‐pot and low‐temperature reduction strategy. The present process/technology is very sensitive to and controlled by the supports and solvents, and the carbon support and acetic acid synergistically play crucial and decisive roles in the fast production of Pd/C catalysts. Also, the used solvents can be recycled and reutilized, which meets the requirements of sustainable chemistry and green economy. When the as‐obtained Pd/CNTs catalyst was used to catalyze the oxidation of benzyl alcohol to benzaldehyde, it achieved a conversion efficiency as high as 99.3 % and a high selectivity up to >99.9 %. The simple, scalable and environmentally friendly strategy can be extended to anchor Pd nanoparticles on various carbon substrates, which sheds a new light on the synthesis of Pd/C catalysts. [ABSTRACT FROM AUTHOR]

This work studies the catalytic properties of Cu and Ni catalysts, as well as the effect of Cu and Ni combination on the activity and selectivity during the aqueous phase hydrogenation of 5-hydroxymethylfurfural (HMF) in a batch reactor, at 60 °C under 30 bar H 2. Catalysts with different Ni/Cu ratios (10 wt%) were synthesized over a high surface area graphite (HSAG). While Ni provides the bimetallic catalyst the capacity for hydrogenation of C O and C C groups, Cu contributes to suppress the hydrogenation of the furan ring, reaching a 99% of selectivity to the partial hydrogenated product, 2,5-di-hydroxymethylfuran (DHMF), over 5Cu5Ni/HSAG. The increase of reaction temperature (180 °C) conduced to the hydrolytic ring-opening and rearrangement of HMF. Under such reaction conditions, monometallic Ni afforded the highest yield towards the hydrogenative rearrangement product, 3-hydroxymethylcyclopentanone (81%). However, Cu and CuNi bimetallic catalysts were less reactive to the ring-rearrangement reaction and showed higher tendency to deactivation, especially when the HMF supplier contain sulfur impurities. [Display omitted] • There is a synergic effect between Cu and Ni in the partial hydrogenation of 5-hydroxymethylfurfural. • Cu suppresses the C C hydrogenation ability of Ni in favor of the carbonyl hydrogenation product. • Cu and Ni are effective in the ring-opening and rearrangement reactions under additive-free conditions. • The reagent purity influences on the kinetics, products yields and catalyst's recyclability. • Sulfur impurities of the feedstock affect more severely to Cu than Ni catalysts. [ABSTRACT FROM AUTHOR]

Catalyst FeCrO x /C in the course of oxidative dehydrogenation of ethane with carbon dioxide to ethylene at temperatures of 600–700 °C was found to undergo in situ regeneration with CO 2 to give a stoichiometric amount of CO by the Boudoir–Bell reaction with the surface carbonized material. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Nitrogen-doped carbon on CNTs enhances the activation of iron particles for Fischer-Tropsch synthesis of C 2 –C 4 olefins. • Addition of sodium and sulfur leads to tandem promotion and highly active and selective iron-based Fischer-Tropsch catalysts. • Iron time yields are as high as 94∙10−5mol CO g Fe -1 s-1 (340 °C, 10 bar, H 2 /CO = 2). Abstract Carbon nanotubes with various surface modifications are utilized as supports for iron species and the resulting catalysts are used for the Fischer-Tropsch synthesis of C 2 –C 4 olefins with and without the addition of Na and S promoters. A layer of nitrogen-doped carbon on the carbon nanotube surface serves as an efficient promoter independent of the presence of Na/S. It leads to significantly faster catalyst activation as compared to the tubes without such a layer resulting from an electronic junction effect at the iron-support interface. The tandem of Na/S- plus N-doped carbon promoted catalysts provide a record high iron-time-yield of up to 94∙10−5mol CO g Fe -1 s-1 under industrially relevant Fischer-Tropsch conditions (340 °C, 10 bar, H 2 /CO = 2) and slow deactivation over more than 185 h of time on stream. Furthermore, this tandem promotion leads to enhanced C 2 –C 4 olefin and C 5+ selectivity along with reduced methanization as compared to the solely Na/S-promoted catalysts. [ABSTRACT FROM AUTHOR]

Carbon has acquired considerable attention in view of its application as supports for platinum (Pt) catalyst in direct methanol fuel cells (DMFCs) with promising renewable energy source due to their high surface area and excellent chemical stability. However, the progress of carbon supports still needs to move towards the practical utilization of high-performance DMFCs. In the present study, we propose a novel support of nitrogen (N)-doped carbon and nickel (Ni) composites produced from protein using an impregnation process and carbonization to increase the electrical conductivity. To this end, we fabricated the Pt nanoparticles on N-doped carbon and Ni composites (Pt@NC/Ni). To obtain the optimized electrochemical performance, the amount of Ni components into carbon supports was controlled by three types. Specifically, as compared to commercial Pt/C and other samples, the optimized Pt@NC/Ni with the high electrical conductivity of 0.75 S cm −1 shows the lowest onset potential of 0.03 V, the highest anodic current density of 744 mA mg Pt −1 , and an excellent catalytic stability with the highest retention rate of 86%. Accordingly, this novel support provides multiple advantages in terms of the well-dispersed Pt nanoparticles on the surface, N-doping effect of carbon supports, and an increased electrical conductivity by the introduction of Ni components. Therefore, Pt@NC/Ni is a promising novel catalyst to enhance electrochemical performance of methanol oxidation reaction. [ABSTRACT FROM AUTHOR]

Abstract: Developing facile preparation routes and atomic‐level characterization methods for single‐atom catalysts is highly desirable but still challenging. Herein, a general strategy is proposed to construct transition metal single atoms within 1D and 2D carbon supports. The carbon supports, typically graphene and carbon nanotubes, are coated with various transition metal‐containing bimetal hydroxides, followed by polydopamine coating and high‐temperature pyrolysis. X‐ray absorption fine structure spectroscopy measurements and simulations efficiently indicate that single atoms (Co, Fe, or Cu) are captured within the applied carbon supports, distinctively forming exclusive molecule‐type sites. As a proof‐of‐concept application, the obtained catalysts exhibit remarkable performance for electrochemical oxygen reduction reaction, even surpassing commercial Pt/C catalyst. The developed versatile route opens up new avenues for the design of carbon‐based catalysts with definite molecular active sites. The atomic‐level structural identifications provide significant guidance for mechanistic studies toward single‐atom catalysts. [ABSTRACT FROM AUTHOR]

Glycerol electrooxidation was evaluated on Pt electrodeposited over carbon Vulcan (CV), multi-walled carbon nanotubes (MWCNTs), graphene oxide nanoribbons (GONRs), and graphene nanoribbons (GNRs). Different masses of Pt were deposited under the same conditions, producing different surface areas of Pt. The presence of GNRs slightly enhanced the specific activity of the catalyst. By investigating the derivative voltammetry of glycerol, we found that the supports did not shift the onset potential towards lower values. Moreover, we found that the apparent activation energy did not vary by changing the carbon support. In this sense, we rationalized the slight improvement in specific activity of Pt deposited on GNRs as a consequence of the frequency of collision factor due to the availability of Pt over the longitudinal flat surface of nanoribbons, as shown by the high active surface area/mass of electrodeposited Pt ratio. [ABSTRACT FROM AUTHOR]

Abstract: Strategies are presented for single‐pot efficient oxidative functionalization of cyclohexane and alcohols, under mild conditions, catalysed by Au(I) or Au(III) compounds supported on different carbon materials with three different surface treatments. The obtained materials were tested for the oxidation of cyclohexane under mild conditions (room temperature and atmospheric pressure), using an environmentally friendly oxidant (tert‐butyl hydroperoxide, TBHP, 70 % aqueous solution). All materials were very selective to the production of cyclohexanol and cyclohexanone with no trace of by‐products detected. The catalysts were also tested in the selective oxidation of methyl benzyl alcohol, cyclohexanol, and 2‐octanol with TBHP, under microwave irradiation, to the corresponding aldehydes or ketones. In general, better results are obtained for the heterogenised complexes and that the most efficient support is CNT‐ox‐Na. This is the first report on the oxidation of C−H bonds using the mononuclear gold complexes used; only the oxidation of unsaturated units had been reported previously. The sp3‐C−H activation is much more difficult than the oxidation of unsaturated molecules with molecular oxidants. [ABSTRACT FROM AUTHOR]

XP Spectroscopy is used to compare the states of the supported platinum particles in the samples of the Pt/Sibunit catalyst and the Pt/HOPG model system after treating in NO 2 at room temperature and pressure of 3 × 10 −6 mbar. It is shown that in both cases the platinum particles are not oxidized completely. The comparison of the spectra obtained for the Pt/Sibunit sample in the Pt 4f and Pt 3d 5/2 regions with the use of Al K α and Ag L α radiations serves as a basis for an assumption that the particles of platinum after being treated in NO 2 have the core (metallic Pt) − shell (platinum oxides) structure. [ABSTRACT FROM AUTHOR]

Cyclohexanol is an important feedstock in the chemical industry. Highly selective hydrogenation of phenols to cyclohexanol over non-noble metal catalysts remains a challenge. Herein, four distinctive carbon materials, carbon black (CB), activated carbon (AC), activated carbon fiber (ACF) and carbon nanotube (CNT) were selected as catalyst supports to load Ni nanoparticles for effective phenol hydrogenation. The results show that the phenol conversion and cyclohexanol selectivity in aqueous phase hydrogenation reaction at 180 °C for 2 h over 10 wt% Ni/AC catalyst could reach 99.7% and 94.8%, respectively. These values are better than those obtained over 10 wt% Ni/ACF, Ni/CNT and Ni/Al 2 O 3. After surface modification of carbon supports, the catalytic activity and reuse effect of modified catalysts are significantly enhanced and the optimal temperature decreases to 150 °C. This is because that modified carbon supports have abundant surface functional groups so as to provide a high dispersion and stable anchor of ultrafine active Ni nanoparticles (∼12 nm). Phenol hydrogenation catalyzed by different Ni/carbon catalysts conforms to a first-order reaction, and their apparent activation energies are in a range of 49∼68 kJ mol−1 (49 corresponds to the modified catalyst Ni/MAC), which are markedly lower than that of Ni/Al 2 O 3 (∼96 kJ mol−1). The potential mechanism of highly selective hydrogenation of phenol to cyclohexanol in this work is mainly controlled by the reaction kinetics, which is closely related to the different desorption abilities of cyclohexanone and cyclohexanol from the catalysts. [Display omitted] • A nearly 100% phenol conversion and ∼95% cyclohexanol selectivity were achieved over Ni/carbon catalysts. • Surface modification of carbon supports enhanced the catalytic activity and reuse effect of Ni/carbon catalysts. • The reaction thermodynamics and kinetics of phenol hydrogenation were systematically investigated. • The activation energies of 10 wt% Ni/carbon catalysts (49–68 kJ mol−1) were lower than that of Ni/Al 2 O 3 (∼96 kJ mol−1). • The mechanism of selective hydrogenation of phenol to cyclohexanol over Ni/carbon catalysts has been proposed. [ABSTRACT FROM AUTHOR]

The effect of the choice of carbon support (activated carbon, carbon nanofiber, graphite, and multiwalled carbon nanotube) on the formation of rhenium carbide was evaluated in the hydrodeoxygenation of guaiacol, a pyrolysis oil model compound. Catalysts were prepared by incipient wetness impregnation, carburized at 650ºC under a 25/75 mixture of ethylene/hydrogen, and characterized by XRD, N 2 -physisorption, TPD, TPR, NH 3 -TPD, and XPS. The characterization results gave evidence that the choice of support affected the carburization of rhenium, a likely consequence of the nature of oxygen function groups on the supports. Indeed, poor carburization of Re occurred over the carbon nanofiber support, which was rationalized by a lack of carboxylic groups on the support. The study showed that the sites mainly responsible for converting guaiacol could be identified by quantification of CH 4 mass signals during TPR measurements. This is an important finding to unravel the critical properties responsible for the HDO catalysis of carburized Re. Most of the catalysts were effective at converting guaiacol to phenol and a few, especially Re/MWCNT-O+ and Re/HSAG, were active for the hydrogenolysis of phenol to benzene (with benzene selectivity reaching 50% at guaiacol conversion of 98%). This indicates that this class of catalysts show great promise in converting guaiacol to desirable aromatic hydrocarbons. [Display omitted] • Effect of the carbon support over rhenium carburization was investigated. • Different carbide could be obtained depending on the support. • Oxygen-functional groups affect the carburization degree. [ABSTRACT FROM AUTHOR]

The work investigated performances of several CoMoP and CoMoW catalysts supported on different carbon materials in catalytic hydrodeoxygenation (HDO) of pyrolysis oil in supercritical ethanol using formic acid as an in-situ hydrogen source. Among them, the CoMoP catalyst supported on ZnCl 2 activated sawdust carbon (ASC-Zn) and the CoMoW catalyst supported on multi-walled carbon nanotubes (MWNTs) showed the best HDO performance at both 300 °C and 350 °C for 2 h, obtaining higher upgraded oil yield, lower oxygen contents of the upgraded oils, and higher degrees of deoxygenation (DOD). Whereas the stability tests with three HDO cycles showed that both catalysts were slightly deactivated likely by active metals leach-out or coke/carbon deposition on active sites of the catalysts. [Display omitted] • CoMoP & CoMoW catalysts supported on different carbon materials were synthesized. • HDO of pyrolysis oil in supercritical ethanol with in-situ H 2 source was studied. • CoMoW/MWNTs and CoMoP/ASC-Zn exhibited the best performance. • These two catalysts achieved 84% and 86% degree of deoxygenation at 350 °C. • Future improvement on the catalyst stability/reusability is needed. [ABSTRACT FROM AUTHOR]

The mass kinetic current density (mass JK) of most extensively reported M−N/C catalysts (M represents non-precious metal elements such as Fe, Co, and Cu), a potential alternative to noble metal catalysts in fuel cells, is poorer than that of commercial Pt/C. Thus, deep understanding of the intrinsic roles of carbon supports may contribute to the development of M−N/C catalysts from a practical point of view. Herein, the routinely used carbon supports, i.e. carbon black (CB) and carbon nanotubes (CNT) that have different morphology and crystallinity, were investigated to uncover the factors that affected the mass JK of Fe−N/C in electrocatalytic oxygen reduction. When immobilized on CB, the ionic liquids-derived Fe−N/C exhibited an enhanced mass JK (4.45 A g−1 at 0.80 V vs. RHE) by a factor of 2.14 times, comparable to that of Pt/C (5.79 A g−1) and higher than most reported M−N/C catalysts to our best knowledge. In contrast, the CNT support system showed no improvement. It was revealed that a compatible interface between the Fe−N/C precursors and the carbon supports was vital to ensure in-situ growth of a uniform catalyst layer on the supports during pyrolysis. This subsequently promotes the mass JK by exposing more embedded active sites and introducing favorable slit pores for effective mass-diffusion. This work would be promising to address the long-term overlooked challenge of the low mass JK of M−N/C catalysts in replacing noble-metal catalysts for practical fuel cell applications. [ABSTRACT FROM AUTHOR]

In this study, we discuss the influence of various carbon supports for Pt on proton exchange membrane (PEM) fuel cell performance. Here, Pt supported on various carbon nano-forms [Pt/carbon black (Pt/CB), Pt/single-walled carbon nanotubes (Pt/SWCNT), Pt/multi-walled carbon nanotubes (Pt/MWCNT) and Pt/graphene (Pt/G)] are synthesized by a facile, single step, microwave-assisted, modified chemical reduction route. Their physical, chemical and electrochemical characteristics pertaining to oxygen reduction reaction (ORR) catalytic activity and stability in PEM fuel cell are studied in detail by various techniques and compared. The study shows that the different carbon supports does not significantly affect the Pt particle size during synthesis, but leads to different amount of defective sites in the carbon framework which influence both the availability of active metal nano-catalysts and metal-support interaction. In-situ electrochemical investigations reveal that the different carbon supports influence both ORR catalytic activity and stability of the catalyst. This is further corroborated by the demonstration of varying polarization characteristics on PEM fuel cell performance by different carbon supported Pt catalysts. This study reveals MWCNT as the most suitable carbon support for Pt catalyst, exhibiting high activity and stability for ORR in PEM fuel cell. [ABSTRACT FROM AUTHOR]

Catalytic layers are prepared by the vacuum ion-beam-assisted deposition of tin and platinum onto carbon-based AVCarb® Carbon Fiber Paper P50 and Toray Carbon Fiber Paper TGP-H-060 T supports to produce electrocatalysts for direct methanol and ethanol fuel cells with a polymer-membrane electrolyte. The layers are formed in the mode of ion-assisted deposition, wherein ions of the deposited metal are used as ions assisting deposition. Metal deposition is performed from a neutral vapor fraction, while mixing of the deposited layer with the substrate by accelerated ions of the same metal is carried out from the vacuum arc discharge plasma of a pulsed electric arc ion source. The morphology and composition of the layers is studied using scanning electron microscopy, electron probe microanalysis, X-ray fluorescence analysis, and Rutherford backscattering spectrometry. It is demonstrated by means of voltammetric measurements that the resulting electrocatalysts exhibit activity in the oxidation of methanol and ethanol. [ABSTRACT FROM AUTHOR]

Bimetallic Pd-Ru/C catalysts prepared with different carbon supports were shown to be much more active in the liquid-phase hydrogenation of benzaldehyde in comparison with their monometallic analogs. In the case of systems based on nanoglobular carbon, the synergistic effect manifested itself as an increased selectivity for benzyl alcohol (86–90%) at a complete conversion of benzaldehyde, whereas the catalysts containing carbon nanotubes were highly active in hydrogenolysis of the C O bonds, which caused an increased yield of toluene (up to 56%). The synergistic effect between palladium and ruthenium in the reaction under study can be related to the changes in the electronic and dispersion state of the supported metals upon interaction with each other and formation of Pd-Ru alloy. In terms of the electronic factor, the enhanced catalytic performance of bimetallic systems can be a result of facilitation of electrophilic activation of the C O bond in benzaldehyde owing to an increased fraction of the electron-deficient palladium species. The nature of carbon support was shown to affect the electronic state of supported metals and thus catalytic properties of bimetallic Pd-Ru/C systems. [ABSTRACT FROM AUTHOR]