Preferential oxidation of CO in H2-rich steam is considered to be a promising method to deeply remove trace CO in excess H2 that would poisons the anodic Pt electrodes of proton-exchange-membrane fuel cells (PEMFCs). Ruthenium catalysts are promising catalysts for PROX reaction. However, the development of efficient catalysts and the identification of the active sites during reaction remains a great challenge. Herein we report a highly active and stable Ru/TiO2 catalysts prepared by chemical reduction synthesis method with reduction pretreatment at appropriate temperature. The reaction was carried out under the feed gas consisted of 1 vol.% CO, 1 vol.% O2, 50 vol.% H2 and N2 balance, with the weight hourly space velocity (WHSV) of 60000 mL h-1 g-1. The Ru/TiO2-H200 catalysts achieved complete removal of CO in range of 90–170 °C and fitted well with the typical temperature window for practical PEMFC operations. Detailed characterizations indicated that the lowered Ru chemical valance induced by appropriate reduction pretreatment would lead to enhanced electronic metal-support interactions (EMSIs). The increased electron density would strengthen the CO adsorption on Ru nanoparticles and hence facilitate the enhancement of activity. Based on the in-situ DRIFT spectroscopy, the exposed Ru sites are active for both CO oxidation and CO methanation reaction, while the interfacial Ru sites are inert under PROX reaction condition.

Electronic metal-support interaction promotes the performance on Ru/TiO2 catalysts for preferential oxidation of CO in H2 (PROX)

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

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