MgF2-Modified Hydrotalcite-Derived Composites Supported Pt-In Catalysts for Isobutane Direct Dehydrogenation

Here, a simple method was developed to prepare an MgF2-modified hydrotalcite-derived composite, which was used as support for the Pt-In catalyst for isobutane direct dehydrogenation. The catalysts, composites, and their precursors were characterized by numerous characterization techniques. The results provided evidence for the MgF2 promoter effect on the physical–chemical properties and dehydrogenation performance of the supported Pt-In catalysts. The catalyst with MgF2 shows exceptional isobutene selectivity that can be stabilized at 95%, and the conversion increases from 50% to 58% during the reaction process. Moreover, the existence of MgF2 plays an important role in the resistance to coke formation and Pt sintering by improving the Pt dispersion, inhibiting the reduction of the In3+ species, and adjusting the acidity of the catalyst.

DRIFTS study of Fe promoter effect on Rh/Al2O3 catalyst for C2 oxygenates synthesis from syngas

DRIFTS experiments such as CO adsorption, CO-TPSR and CO+H2 were designated to study the effect of Fe promoter on the key steps of C2 oxygenates formation from syngas. The CO adsorption results demonstrated that Fe weakened CO adsorption and especially the bridging adsorption. It was found in CO-TPSR experiments that the catalyst with lower Fe loading is more easily dissociated while the ones with higher Fe loading own stronger hydrogenation activity. Moreover, it was observed by CO+H2 experiments that Fe plays a role in stabilizing the lineally adsorbed CO species and decreasing the CO desorption rate. The catalytic performance results indicated that when Fe content is 4wt. %, the selectivity of total C2 oxygenates is the highest, which was in accordance with the DRIFTS results.