The mission of the Center for Hybrid Approaches in Solar Energy to Liquid Fuels (CHASE) is to develop molecule/material hybrid photoelectrodes for cooperative sunlight-driven generation of liquid fuels from CO2, N2, and H2O. Specifically, we are pairing light-absorbing semiconductor materials with surface-anchored, fuel-producing molecular catalysts that will operate in tailored microenvironments using a multi-catalyst cascade approach to access liquid fuels. Since CHASE is using visible light-absorbing semiconductor substrates (e.g., Si), mid-IR spectroscopy is an important technique for characterizing the functionalized surfaces, determining catalytic mechanisms, and monitoring the progress of catalysis by detecting intermediates/products. Transmission IR spectroscopy of a catalyst monolayer on a planar surface results in extremely weak signals. CHASE is therefore using multiple reflection Attenuated Total Reflection (ATR) IR spectroscopy of catalysts directly attached to a Si ATR crystal to achieve improved IR signals. This has involved the design and fabrication of a new ATR-IR spectroelectrochemical (ATR-IR-SEC) cell in which a functionalized, surface-doped Si ATR crystal is the working (photo)electrode. Here, we present our recent work on (i) the design and fabrication of the new ATR-IR-SEC cell, (ii) the diffusional surface doping of Si ATR crystals for use in the cell, and (iii) the acquisition of ATR-IR-SEC spectra of surface-bound CO2 reduction catalysts under applied bias with and without illumination.

Development of an ATR-IR spectroelectrochemical cell for the characterization of CO2 reduction catalysts on silicon photoelectrode surfaces

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.