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Amorphous nano-metal catalysts often exhibit appealing catalytic properties, because the intrinsic linear scaling relationship can be broken. However, accurate control synthesis of amorphous nano-metal catalysts with desired size and morphology is a challenge. In this work, we discover that Cu(0) could be oxidized to amorphous CuxO species by supercritical CO2. The formation process of the amorphous CuxO is elucidated with the aid of machine learning. Based on this finding, a method to prepare Cu nanoparticles with an amorphous shell is proposed by supercritical CO2 treatment followed by electroreduction. The unique feature of this method is that the size of the particles with amorphous shell can be easily controlled because their size depends on that of the original crystal Cu nanoparticles. Moreover, the thickness of the amorphous shell can be easily controlled by CO2 pressure and/or treatment time. The obtained amorphous Cu shell exhibits high selectivity for C2+ products with the Faradaic efficiency of 84% and current density of 320 mA cm−2. Especially, the FE of C2+ oxygenates can reach up to 65.3 %, which is different obviously from the crystalline Cu catalysts. Amorphous metal catalysts often exhibit appealing catalytic properties, however, accurate control synthesis of amorphous nano-metal catalysts is a challenge. Here, the authors report a feasible strategy to prepare the amorphous Cu catalysts by supercritical CO2 treatment followed by electroreduction. The resulted catalyst shows high selectivity towards multi-carbon products for CO2 electroreduction. [ABSTRACT FROM AUTHOR]

Developing electrocatalytic reactions with high‐efficiency can make important contributions to carbon neutrality. However, poor long‐term stability of catalysts is a bottleneck for its practical application. Herein, an "in situ periodic regeneration of catalyst (PR‐C)" strategy is proposed to give long‐term high efficiency of CO2 electroreduction to generate C2+ products over Cu catalyst by applying a positive potential pulse for a short time periodically in the halide‐containing electrolyte. The high Faradaic efficiency (81.2 %) and current density (22.6 mA cm−2) could be maintained completely at least 36 h, while the activity and selectivity decreased continuously without using the PR‐C method. Control experiments and operando characterization demonstrated that the surface structure and oxidation state of Cu could be recovered periodically by the PR‐C method, which was beneficial for CO2 activation and C−C coupling. [ABSTRACT FROM AUTHOR]

Electrochemical reduction of CO2 by renewable electricity offers a promising way to settle excessive greenhouse gases and achieve carbon neutrality under a mild environment. Cu-based catalysts have a unique catalytic activity towards multicarbon (C2+) products in the CO2 electroreduction reaction and are widely studied to promote the corresponding selectivity and activity. Here we report a F-doped Cu (F–Cu) catalyst to improve C2+ products in CO2 electroreduction. A high C2+ product (mainly ethylene and ethanol) faradaic efficiency of 70.4% was achieved on the F–Cu catalyst with a high current density (above 400 mA cm−2) in the flow-cell system. The in situ surface enhanced Raman spectroscopy results and electrochemical performance analysis demonstrated that CO2 could be reduced into CO at low potentials and the adsorption of CO could be strengthened on F–Cu, which is beneficial to the subsequent C–C coupling step and formation of the C2+ products. [ABSTRACT FROM AUTHOR]

Using renewable electricity to drive CO2 electroreduction is an attractive way to achieve carbon‐neutral energy cycle and produce value‐added chemicals and fuels. As an important platform molecule and clean fuel, methanol requires 6‐electron transfer in the process of CO2 reduction. Currently, CO2 electroreduction to methanol suffers from poor efficiency and low selectivity. Herein, we report the first work to design atomically dispersed Sn site anchored on defective CuO catalysts for CO2 electroreduction to methanol. It exhibits high methanol Faradaic efficiency (FE) of 88.6 % with a current density of 67.0 mA cm−2 and remarkable stability in a H‐cell, which is the highest FE(methanol) with such high current density compared with the results reported to date. The atomic Sn site, adjacent oxygen vacancy and CuO support cooperate very well, leading to higher double‐layer capacitance, larger CO2 adsorption capacity and lower interfacial charge transfer resistance. Operando experiments and density functional theory calculations demonstrate that the catalyst is beneficial for CO2 activation via decreasing the energy barrier of *COOH dissociation to form *CO. The obtained key intermediate *CO is then bound to the Cu species for further reduction, leading to high selectivity toward methanol. [ABSTRACT FROM AUTHOR]

Guided by first‐principles calculations, it was found that Cd single‐atom catalysts (SACs) have excellent performance in activating CO2, and the introduction of axial coordination structure to Cd SACs cannot only further decrease the free energy barrier of CO2 reduction, but also suppress the hydrogen evolution reaction (HER). Based on the above discovery, we designed and synthesized a novel Cd SAC that comprises an optimized CdN4S1 moiety incorporated in a carbon matrix. It was shown that the catalyst exhibited outstanding performance in CO2 electroreduction to CO. The faradaic efficiency (FE) of CO could reach up to 99.7 % with a current density of 182.2 mA cm−2 in a H‐type electrolysis cell, and the turnover frequency (TOF) value could achieve 73000 h−1, which was much higher than that reported to date. This work shows a successful example of how to design highly efficient catalysts guided by theoretical calculations. [ABSTRACT FROM AUTHOR]

Cu(OH)2/CuO nanocomposite-derived Cu2O/Cu was highly efficient for CO2 electroreduction to C2 products. The highest faradaic efficiency and current density could reach 64.5% and 26.2 mA cm−2, respectively. By changing the calcination time, moderate grain boundary density and the Cu+/Cu0 ratio in catalysts can be controlled, leading to a large number of active sites and low interfacial charge transfer resistance. [ABSTRACT FROM AUTHOR]

Abstract: Electrochemical reduction of CO2 into value‐added product is an interesting area. MoP nanoparticles supported on porous carbon were synthesized using metal–organic frameworks as the carbon precursor, and initial work on CO2 electroreduction using the MoP‐based catalyst were carried out. It was discovered that MoP nanoparticles supported on In‐doped porous carbon had outstanding performance for CO2 reduction to formic acid. The Faradaic efficiency and current density could reach 96.5 % and 43.8 mA cm−2, respectively, when using ionic liquid 1‐butyl‐3‐methylimidazolium hexafluorophosphate as the supporting electrolyte. The current density is higher than those reported up to date with very high Faradaic efficiency. The MoP nanoparticles and the doped In2O3 cooperated very well in catalyzing the CO2 electroreduction. [ABSTRACT FROM AUTHOR]

Acetic acid is an important bulk chemical and synthesis of acetic acid via methanol hydrocarboxylation with CO2 and H2 is a very promising route. In this work, we studied the reaction over a number of catalytic systems. It was found that Rh2(CO)4Cl2 with 4-methylimidazole (4-MI) as the ligand was very efficient in the presence of LiCl and LiI. Acetic acid began to form at 150 °C. The TOF was as high as 26.2 h−1 and the yield of acetic acid could reach 81.8% at 180 °C. The catalytic system had obvious advantages, such as simplicity, high activity and selectivity, milder reaction conditions, and less corrosiveness. The excellent cooperation of CO and Cl− in Rh2(CO)4Cl2, suitable basicity and aromaticity of the ligand 4-MI, and the hydrogen bonding ability of Cl− were crucial for the outstanding performance of the catalytic system. The control experiments showed that the reaction did not proceed via the CO pathway. [ABSTRACT FROM AUTHOR]