Crystal facet engineering coexposed CuIn (200) and In (101) in CuIn alloy nanocatalysts enabling selective and stable CO2 electroreduction

The electrocatalytic carbon dioxide reduction reaction (eCO2RR) into high-value-added chemicals and fuels is a promising strategy to mitigate global warming. However, it remains a significant stumbling block to the rationally tuning lattice plane of the catalyst with high activity to produce the target product in the eCO2RR process. To attempt to solve this problem, the CuIn bimetallic alloy nanocatalyst with specifically exposed lattice planes is modulated and electrodeposited on the nitrogen-doped porous carbon cloth by a simple two-step electrodeposition method, which induces high Faraday efficiency of 80% towards HCOO− (FEHCOO−) with a partial current density of 13.84 mA cm−2 at −1.05 V (vs. RHE). Systematic characterizations and theoretical modeling reveal that the specific coexposed CuIn (200) and In (101) lattice facets selectively adsorbed the key intermediate of OCHO*, reducing the overpotential of HCOOH and boosting the FEHCOO− in a wide potential window (−0.65–−1.25 V). Moreover, a homogeneous distribution of CuIn nanoparticles with an average diameter of merely ∼3.19 nm affords exposure to abundant active sites, meanwhile prohibiting detachment and agglomeration of nanoparticles during eCO2RR for enhanced stability attributing to the self-assembly electrode strategy. This study highlights the synergistic effect between catalytic activity and facet effect, which opens a new route in surface engineering to tune their electrocatalytic performance.