Towards molecular understanding of local chemical environment effects in electro- and photocatalytic CO 2 reduction

Substantial progress has recently been made in the general understanding of the interfacial CO 2 reduction reaction (CO 2 RR) in electro- and photocatalysis, but the influence of the local chemical environment and its effects on the catalytic interface at the molecular level remains largely elusive. Here, we introduce a classification scheme to group different aspects influencing the interfacial CO 2 RR thermodynamics and kinetics. This categorization allows a systematic survey of the literature focusing on the local chemical environment encompassing surface effects (adsorbates, support), solution interactions (electrolyte constituents) and three-dimensional chemical surroundings (polymers, metal organic frameworks (MOFs), covalent organic frameworks (COFs)). The review concludes with an outlook discussing possible future concepts for next-generation electrocatalytic and photocatalytic CO 2 RR.