The nature of active sites for carbon dioxide electroreduction over oxide-derived copper catalysts

Dongfang Cheng,Geoffrey A Ozin,Jinlong Gong,Hui Gao,Piaoping Yang,Zhi-Jian Zhao,Lulu Li,Tuo Wang,Zhipan Liu,Xin Chang,Gong Zhang,Sai Chen,Sihang Liu

doi:10.1038/s41467-020-20615-0

Abstract

The active sites for CO2 electroreduction (CO2R) to multi-carbon (C2+) products over oxide-derived copper (OD-Cu) catalysts are under long-term intense debate. This paper describes the atomic structure motifs for product-specific active sites on OD-Cu catalysts in CO2R. Herein, we describe realistic OD-Cu surface models by simulating the oxide-derived process via the molecular dynamic simulation with neural network (NN) potential. After the analysis of over 150 surface sites through NN potential based high-throughput testing, coupled with density functional theory calculations, three square-like sites for C–C coupling are identified. Among them, Σ3 grain boundary like planar-square sites and convex-square sites are responsible for ethylene production while step-square sites, i.e. n(111) × (100), favor alcohols generation, due to the geometric effect for stabilizing acetaldehyde intermediates and destabilizing Cu–O interactions, which are quantitatively demonstrated by combined theoretical and experimental results. This finding provides fundamental insights into the origin of activity and selectivity over Cu-based catalysts and illustrates the value of our research framework in identifying active sites for complex heterogeneous catalysts.

Highlights

The active sites for CO2 electroreduction (CO2R) to multi-carbon (C2+) products over oxidederived copper (OD-Cu) catalysts are under long-term intense debate
The development of machine-learning-based new calculation methods is a frontier in the field of theoretical catalysis, at the same time, a promising route to analysis the active sites in complex heterogeneous catalytic system[17,18]
A realistic surface model is the prerequisite for the exact analysis of atomic structure of active sites

Summary

Introduction

The active sites for CO2 electroreduction (CO2R) to multi-carbon (C2+) products over oxidederived copper (OD-Cu) catalysts are under long-term intense debate. We break the spatiotemporal limitation of QM and use molecular dynamic simulation with global neural network potential (NN-MD)[20,21] to simulate the whole dynamic evolution of the surface from copper oxide to OD-Cu. By combining NN potential-based high-throughout testing, density functional theory calculations and experimental studies, we establish the linkage correlations between the atomic structure of active sites and their catalytic activities for specific products in CO2R over OD-Cu catalysts.

Results

Conclusion