Surface reconstruction and the effect of Ni-modification on the selective hydrogenation of 1,3-butadiene over Mo2C-based catalysts†
In the current study, Mo2C, NiMo2C, H–Mo2C and H–NiMo2C were synthesized to understand the effects of Ni modification and synthesis routes. The catalysts were characterized by XRD, N2-physisorption, SEM, TEM, XPS and pulse CO chemisorption and were evaluated in a fixed-bed reactor. The catalysts are found to undergo surface reconstruction during the reaction–regeneration process and thereafter exhibit better stability. Among the investigated catalysts, H–NiMo2C exhibits the best stability and H–Mo2C exhibits the highest butene selectivity. The electronic effect induced by Ni-modification via the conventional route could enhance the butene selectivity. The high butene selectivity over the unmodified H–Mo2C via the HA-TPC route may stem from surface vacancies and the presence of α-Mo1−xC. This work for the first time reports the 1,3-butadiene hydrogenation over Mo2C-based catalysts under steady state conditions; the surface reconstruction and the effect of Ni-modification will inspire us to develop industrial non-noble metal catalysts.