In situ XANES study of methanol decomposition and partial oxidation to syn-gas over supported Pt catalyst on SrTiO3 nanocubes

摘要

A catalyst of Pt nanoparticles was prepared by atomic layer deposition on SrTiO3 nanocuboids and tested for methanol decomposition and partial oxidation. The catalyst had uniform nanoparticle size of 1.58 ± 0.37 nm and a Pt (111) surface. In situ X-ray absorption near-edge spectroscopy (XANES) measured in a temperature-programmed reduction showed that the Pt particles were easily reduced. However, the as-received catalyst, a reduced catalyst, and an oxidized catalyst all had catalytic activity, differing slightly in methanol conversion and product selectivity. In situ XANES also revealed that CO adsorbed on the Pt sites was the only observed surface species during both methanol decomposition and partial oxidation. It seemed that the breakage of CH and OH bonds overwhelmingly occurred once methanol was adsorbed, forming H2 and adsorbed CO. The latter was then released from the catalyst surface or was oxidized to CO2 when O2 was present.