Titania-Carbon Nitride Interfaces in Gold-Catalyzed CO Oxidation

• DOI: 10.1021/acsami.1c16159
• Publication Date: 2021-12-17T15:16:44Z
• Authors: Pablo Jiménez-Calvo; Loïc Michel; Valérie Keller; Valérie Caps
• Keywords: PROX; Carbon nitride; Carbon fibers

Gold-catalyzed CO oxidation is a reaction of both practical and fundamental interest. In particular, rate-determining oxygen activation pathways have attracted lot attention. They been found to depend on the surface chemistry catalyst support, titania providing most active catalysts carbon nitride leading inactive catalysts. Here, we show that C3N4-TiO2 composites with rather similar chemistries can be engineered by using nanotubes as hard templates performing polycondensation melamine dicyandiamide in air ammonia. By varying C3N4 content from 2 75 wt %, mesoporosity tuned 8 40 nm. A systematic study turnover numbers absence presence hydrogen over loaded well-calibrated 2-4 nm gold nanoparticles clearly shows (1) chemical composition support has much less impact PROX (preferential excess hydrogen) than dry oxidation, (2) NH2-terminated supports are OH-terminated PROX, (3) hydrogen/water-mediated C3N4-based Au catalysts, (4) activity requires large porosity (40 nm), which suggests involvement larger intermediates usually postulated peroxo-type species.