Abstract
Two-dimensional atomically thin hexagonal boron nitride (h-BN) monolayers have attracted considerable research interest. Given the tremendous progress in the synthesis of h-BN monolayers on transition metals and their potential as electrocatalysts, we investigate the electrocatalytic activities of h-BN/Ni, h-BN/Co, and h-BN/Cu interfaces for CO2 reduction by the first-principles density functional theory. We find that with the h-BN monolayer on the metal, electrons transfer from the metal to the interface and accumulate under the B atoms. By calculating the binding energies of three key intermediates (H, HCOO, and COOH) for hydrogen evolution and CO2 reduction, we find that H binding on the metal can be significantly weakened by the h-BN monolayer, preventing the hydrogen evolution reaction (HER). However, the binding strength of HCOO is strong on both the metal and h-BN/metal, especially for Ni and Co, promoting the CO2 reduction channel. On the basis of the free-energy diagrams, we predict that h-BN/Ni and h-BN/Co will have very good electrocatalytic activities for CO2 reduction to HCOOH, while the competitive HER channel is filtered out by the surface h-BN monolayer. Our study opens a new way for selective electroreduction of CO2 via the interface engineering of the h-BN/metal system.
Original language | English |
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Pages (from-to) | 6694-6700 |
Number of pages | 7 |
Journal | ACS Applied Materials and Interfaces |
Volume | 10 |
Issue number | 7 |
DOIs | |
State | Published - Feb 21 2018 |
Funding
This work was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences. This research used resources of the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy under contract no. DE-AC02-05CH11231.
Keywords
- earth-abundant transition metals
- electrochemical CO reduction
- first-principles DFT
- h-BN monolayer
- hydrogen evolution reaction
- interfacial materials