Low-loading Pt/β-Mo2C catalyst for ethanol dissociation. Experimental and theoretical characterization

CHASVIN, NILDA; SVENDA, PETR; PRONSATO, MARÍA ESTELA; DIEZ, ALEJANDRA; VOLPE, MARÍA ALICIA; JOHÁNEK, VIKTOR; PISTONESI, CAROLINA

PHYSICAL CHEMISTRY CHEMICAL PHYSICS

ROYAL SOC CHEMISTRY

Lugar: CAMBRIDGE; Año: 2021 vol. 23 p. 23567 - 23575

1463-9076

The adsorption and dissociation of ethanol on Pt/b-Mo2C with a low noble metal loading (0.1 wt%) isstudied in the context of catalytic H2 production from alcohols. X-ray diffraction and experimentalresults indicate that Pt modifies the lattice parameters of b-Mo2C. In line with this, density functionaltheory calculations indicate that the Mo?Mo distances are increased due to the presence of Pt.An experimental X-ray photoelectron spectroscopy study indicates that the chemical state of bothmolybdenum and carbon in Pt/b-Mo2C are very different from those in the Pt-free carbide, which is alsoin agreement with the DFT results, which indicate that the Pt atoms generate a redistribution of chargedensity in their environment. Temperature programmed reaction analysis shows that at temperatureshigher than 530 K, a two-fold increase in the production of H2, CH4 and C2H6 is observed for Pt/bMo2C as compared to b-Mo2C, suggesting a higher catalytic activity for the Pt-containing carbide thanfor the pristine catalyst. Additionally, H2 production from ethanol on Pt/b-Mo2C presents a higheractivation energy (0.64 eV) than that corresponding to pristine molybdenum carbide. In agreement withthis experimental result, climbing image-nudged elastic band (CI-NEB) calculations indicate that theenergy barrier linked to the formation of H2 from ethanol increases with the presence of platinum. It isconcluded that the low Pt loading notably modifies the catalytic pattern of molybdenum carbide,rendering it a highly active catalyst for ethanol decomposition.