In heterogeneous catalysis, the exact chemical nature of the catalyst’s active sites can control the reaction mechanism, which is essential to reach high activity. A recently developed liquid atomic layer deposition technique (L-ALD) leverages atom-by-atom growth regimes to create unique interfacial structures generated with unprecedented atomic precision. The proposed project aims to characterize molecular cluster catalysts prepared in this atom-by-atom manner using XASXRD measurement. Specifically, state-of-the-art operando characterization of a liquid ALD-synthetized Cu/MgOZrO2 catalyst with exceptionally high activity toward CO2 hydrogenation will allow us to identify the nature of the unique active site we have created and better understand the required properties for selective methanol production from CO2.