In situ XAS investigation of Gas-phase Pd Clusters-modified Mesoporous Copper Oxide Inverse Opals for CO2 Reduction into C2+ Products

The objective of this proposal is to use in situ X-ray absorption spectroscopy (XAS) to investigate Cu-Pd tandem electrocatalysts designed for the selective conversion of CO2 into C2+ products. These electrocatalysts consist of mesoporous oxygen-rich copper inverse opals (mCu) synthesized via a colloid templating method whose surface is uniformly decorated with Pd nanoclusters via Cluster Beam Deposition (CBD). We will conduct in situ measurements of X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) at both Cu and Pd K-edges using a specially designed grazing incidence electrochemical flow cell. This will allow us to explore the dynamic electronic and structural properties of the electrocatalysts during electrochemical CO2 reduction (ECR) conditions as a function of Pd loading to enhance our understanding of the structure-activity relationship governing highly active Pd-Cu tandem CO2 electrocatalysts, in their selectivity of C2+ products.