Size, Shape, Facet and Support Dependent Selectivity of Cu nanoparticles in CO2 reduction through multiparameter optimization

This study investigates the limited selectivity of Cu111 surface for C-C bond formation during CO2 reduction and explores factors influencing selectivity using Cu nanoparticles smaller than 2 nm. Optimal nanoparticle size for C-C bond formation on 111 facet with minimal overpotential is determined using density functional theory. Suitable supporting surface to enhance stability and catalytic performance of Cu-based nanoparticles is identified. Various Cu catalyst geometries, including planar surfaces and cuboctahedral, icosahedral, and truncated octahedral Cu nanoparticles, are considered. Size-dependent effects on binding energies of reaction intermediates and hydrogen atoms are examined. Carbon-based surfaces, particularly 2SO2-doped graphene nanoribbons, exhibit stable host for Cu nanoparticle and help in retaining the activity for CO2 reduction. Scaling relations between binding energies of intermediates suggest COOH binding energy as an energy descriptor. Through multiparameter optimization and with the help of parity line and graphical construction Cu38 and Cu79 are found as most promising surface for C2 product generation. Inclusion of 2SO2-doped graphene further increases the activity on Cu38 and Cu79. This study provides insights into factors influencing selectivity and catalytic performance of Cu nanoparticles, aiding the development of efficient catalysts for CO2 reduction.