In situ IR spectroscopy study of ethanol steam reforming in the presence of Pt–Ru/DND nanocatalysts

Ethanol steam reforming (ESR) over a Pt–Ru(0.3%) catalyst supported on detonation nanodiamonds (DNDs) and on DNDs containing no noble metals has been studied. It has been shown that the two catalysts provide the formation of the same products; however, their yield and distribution significantly change after supporting Pt–Ru on DND. The adsorbed species that formed during ESR over DND and the Pt–Ru(2.5%)/DND model catalyst have been studied by in situ high-temperature diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). It has been shown that the ability of pure DND to mediate the ESR process is provided by the carbonyl and carboxyl groups on the DND surface; this feature is the main difference of the Pt–Ru/DND catalytic nanocomposite from catalysts in which Pt and Ru are supported on various oxides. On the basis of a comparison of the results obtained during ESR in a catalytic reactor and in a DRIFTS cell, a mechanism of the process over DND-supported catalysts has been proposed.