Computational Screening of Near-Surface Alloys for CO2 Electroreduction

Zhonglong Zhao, Gang Lu

Index: 10.1021/acscatal.7b03705

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Abstract

Electrochemical conversion of carbon dioxide (CO2) into chemical feedstocks provides an attractive solution to our pressing energy and environment problems. Here, we report that transition metal near-surface alloys (NSAs) are promising catalysts for CO2 electroreduction. Based on first-principles calculations on 190 candidates, we propose a number of NSAs which show promise of highly active and selective catalysts for formic acid, carbon monoxide, methanol, and ethylene production, while simultaneously suppress competing hydrogen evolution reaction (HER). We predict that Pd/W, Au/Hf, and Au/Zr NSAs are more active than most known electrodes for formic acid formation with overpotentials significantly lower than that of HER. Ag/Hf and Ag/Zr are revealed as superior catalysts for the production of carbon monoxide with overpotentials of 0.77 V lower than that on pure Ag electrode. We find that methanol and ethylene can be produced on Ag/Ta and Ag/Nb NSAs whose overpotentials are ∼15% lower than that on Cu (211) surface. On the other hand, their overpotentials for HER are six times more negative than that on Cu (211). The work demonstrates the great potential of transition metal catalysts by modulating their near surface properties.