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Summary Electrocatalytic CO2 reduction reaction (CO2RR) has attained great attention as it can transform the greenhouse gas CO2 to value-added chemicals, such as carbon monoxide, formic acid, ethylene, ethanol, and n-propanol. However, the electrocatalytic performance of materials, especially the metal materials, toward the CO2RR is still limited due to the complex reaction processes and broad product distribution. Very recently, surface modification of metal materials has emerged as an effective way to boost their electrocatalytic CO2RR performance. Herein, recent advances in the surface modification of metal materials, which includes surface molecular functionalization, surface elemental doping, and surface plasma treatment, for CO2RR are presented. The surface modification-induced variations of surface states and electrocatalytic performances of metal materials, together with the underlying mechanisms, are highlighted. It is believed that the development of surface modification could promote the rational design and preparation of advanced CO2RR electrocatalysts toward practical applications.

Over the past few decades, gold-based materials have drawn extensive attention due to their intriguing physical/chemical properties and excellent performance in a broad range of applications. In particular, the remarkable technical progress in synthesis and characterization is promoting the rapid development of gold-based nanoalloys, which are of great significance in catalysis. In this review, we provide a brief overview of the recently reported gold-based nanoalloys, focusing on their general synthetic methods and potential catalytic applications. In particular, the general relationships between material structures/compositions and catalytic performances are discussed in representative chemical reactions, such as the carbon dioxide reduction reaction (CO2RR), oxygen reduction reaction (ORR), hydrogen evolution reaction (HER), oxygen evolution reaction (OER), small organic molecule oxidation reaction, carbon monoxide oxidation reaction, and typical heterogeneous catalytic reactions in chemical engineering. Furthermore, critical challenges and potential opportunities facing gold-based nanoalloys are proposed to provide possible inspiration for future material design towards high performance applications.

Because of the distinct electronic structures and stable chemical properties, rhodium materials are one of the most important noble metal catalysts for various kinds of industrial chemical processe...

An energy-effective polyaniline coated graphite felt (PANI@GF) composite cathode for the electro-Fenton (E-Fenton) process was synthesized through an electro-polymerization method. The electrocatalytic activity of the cathode for the 2e− ORR process was investigated and dimethyl phthalate (DMP) was used as a model substrate to evaluate its performance in the E-Fenton process. The as-prepared PANI@GF composite possessed a three-dimensional porous structure, which is favorable for O2 diffusion, while the large amount of N atoms in the conductive polyaniline (PANI) enhanced 2e− ORR reactivity. The DMP degradation of the E-Fenton system using PANI@GF was significantly enhanced owing to the improvement in ORR performance. The apparent kinetic constant for DMP degradation was 0.0753 min−1, five times larger than that of GF. The optimal carbonization temperature and polymerization time for the preparation of the PANI@GF composite cathode was found to be 900 °C and 1 h, respectively. Measurement conditions are a crucial factor for proper evaluation of cathode electrocatalytic performance. Accordingly, the O2 flow rate, Fe2+ concentration, and pH for DMP degradation were optimized at 0.4 L/min, 1.0 mmol/L, and 3.0, respectively. These results indicate that the present PANI@GF composite cathode is energy-effective and promising for potential use as an E-Fenton system cathode for the removal of organic pollutants in wastewater.

The exploration of efficient nonprecious metal‐based oxygen evolution reaction (OER) electrocatalysts is of great significance. Herein, both size‐ and component‐tuned FeNi oxynitride are prepared and employed for electrocatalytic water oxidation. Combining the excellent metal‐like feature of induced OER activity of nitrides and oxidation resistance performance of oxides, the obtained FeNi oxynitride delivers an outstanding OER performance. The synergistic interplay between Fe, Ni components creates a favorable local coordination environment for OER and decreased sizes enables more active sites exposure. As a result, under 1 M KOH, the optimized material displays highly efficient electrocatalytic OER performance with low overpotential 295 mV (10 mA cm−2 catalytic current density) and considerable durability. These findings open up opportunities to explore other excellent catalysts through multicomponent strong interactions coupled with size control. This work was financially supported by the National NaturalScience Foundation of China (Nos. 21606113 and 21676128),and the International Postdoctoral Exchange Fellowship byChina Postdoctoral Science Foundation (No. 20170055).

Due to their unique activity towards formation of alcohols and hydrocarbons, copper (Cu) based catalysts have been widely used in the electrochemical reduction of carbon dioxide (ERCD). Cu foam naturally possesses three-dimensional (3D) porous structure and catalytically active Cu elements, exhibiting very good catalytic ability for ERCD. Herein, nanostructured self-supporting Cu electrodes with Cu foam as the substrate, with progressive morphologies of nanowires (CuNW), nanosheets (CuNS) and nanoflowers (CuNF), are in-situ prepared by simply adjusting the reaction time in a strongly alkaline oxidizing solution. It is found that the performance and products distribution of ERCD are affected by both the morphology of the as prepared nanostructured self-supporting Cu electrodes and the electrolyte species. As electrode micromorphology evolves from nanowire to nanoflower, the initial electrode potential required for C2 products generation shifts to more positive values. The CuNS electrode shows the highest Faradaic efficiency (FE) of 86.9% at −0.4 V (vs. RHE) and superior performance, owing to its nanosheet morphology that can better stabilize the intermediate state products. Moreover, both total FE and products distribution are affected by the electrolyte anion species. The highest total FE in the investigated electrolyte on CuNS electrode obeys the following order: KHCO3 (86.9%, −0.4 V (vs. RHE)) > KCl (54.7%, −0.5 V (vs. RHE)) > KH2PO4 (1.0%, −0.9 V (vs. RHE)). In 1.0 mol L−1 KHCO3, the CuNS electrode shows a very complex products distribution; in 1.0 mol L−1 KCl, the products distribution can be feasibly controlled by the applied potential; while in 1.0 mol−1 L KH2PO4, ERCD is almost totally suppressed by hydrogen evolution reaction (HER). It is the first time that the CuNS electrodes are applied for ERCD with low cost, simple synthesis, easy scale-up and high activity. Combined with the flexible control ability in FE and products distribution, CuNS electrode possesses great potential for the industrial application of ERCD.