Atomic Dispersed Hetero‑Pairs for Enhanced Electrocatalytic CO_(2)Reduction

Electrochemical carbon dioxide reduction reaction(CO_(2)RR)involves a variety of intermediates with highly correlated reaction and ad-desorption energies,hindering optimization of the catalytic activity.For example,increasing the binding of the*COOH to the active site will generally increase the*CO desorption energy.Breaking this relationship may be expected to dramatically improve the intrinsic activity of CO_(2)RR,but remains an unsolved challenge.Herein,we addressed this conundrum by constructing a unique atomic dispersed hetero-pair consisting of Mo-Fe di-atoms anchored on N-doped carbon carrier.This system shows an unprecedented CO_(2)RR intrinsic activity with TOF of 3336 h−1,high selectivity toward CO production,Faradaic efficiency of 95.96%at−0.60 V and excellent stability.Theoretical calculations show that the Mo-Fe diatomic sites increased the*COOH intermediate adsorption energy by bridging adsorption of*COOH intermediates.At the same time,d-d orbital coupling in the Mo-Fe di-atom results in electron delocalization and facilitates desorption of*CO intermediates.Thus,the undesirable correlation between these steps is broken.This work provides a promising approach,specifically the use of di-atoms,for breaking unfavorable relationships based on understanding of the catalytic mechanisms at the atomic scale.

Applying machine-learning screening of single transition metal atoms anchored on N-dopedγ-graphyne for carbon monoxide electroreduction toward C_(1)products

Carbon monoxide electroreduction(COER)has been a key part of tandem electrolysis of carbon dioxide(CO_(2)),in which searching for high catalytic performance COER electrocatalysts remains a great challenge.Herein,by means of density functional theory(DFT)computations,we explored the potential of a series of transition metal atoms anchored on N-dopedγ-graphyne(TM@N-GY,TM from Ti to Au)as the COER electrocatalysts.We found that the final product selectivity of these single-atom catalysts depended on the position of the metal atom in the periodic table,with metals in the front and middle of each periodic period exhibiting high selectivity for CH_(4),while metals in the back producing CH_(3)OH.Machine learning(ML)found that metal atomic number was intrinsic to the difference in COER performance of these single-atom catalysts(SACs).The free energy changes showed that Mn@N-GY and Ni@N-GY exhibited outstanding COER catalytic performance for producing CH_(4)and CH_(3)OH,respectively.Our results provide theoretical and experimental guidance for designing efficient COER catalysts to generate C_(1)products.

室温液态金属合成纳米多孔铜铟异质结构材料应用于高性能二氧化碳转化合成气

纳米多孔金属作为电催化剂使用时表现出了优异的性能.我们报道了一种利用共熔镓铟合金和铜基底制备而成的自支撑铜铟双金属多孔异质结构材料.该多孔铜铟异质结构电催化剂具有良好的二氧化碳转化为合成气的性能.通过调整工作电压,可以使氢气和一氧化碳的比例控制在0.47–2.0之间.且该催化剂非常稳定,经过70小时连续测试后还可以保持96%的电流密度.密度泛函理论计算表明,得益于这种铜铟异质结构的存在,铜表面电荷发生了转变,形成了Cu^(δ)和Cu0等不同位点,从而协同作用分别增强了催化剂生成一氧化碳和氢气的能力.本工作可为多孔金属异质结构电催化剂的设计提供新思路.