Radio-frequency thermal plasma-induced novel chainmail-like core-shell MoO2 as highly stable catalyst for converting syngas to higher alcohols

Abstract

A novel core-shell catalyst with crystalline MoO2 core and chainmail-like amorphous MoOX shell (noted as MoO2-Pla) was prepared by radio-frequency induction thermal plasma method, and its catalytic performance for higher alcohols synthesis from syngas (CO and H2) was compared with that of the MoO2 catalysts synthesized by hydrothermal method and temperature programed reduction method (noted as MoO2-Hyd and MoO2-TPR). It was found that the chainmail-like shell formed under such extreme condition was both active to the reaction and inert to the thermal sintering, which was very fascinating and significantly different from those of the previous reported core-shell catalysts. The unusual amorphous species in the shell increased the CO conversion of MoO2-Pla catalyst by 109 and 213.5%, respectively, compared with MoO2-Hyd and MoO2-TPR. More importantly, the shell formed under such ultra-high temperature (over 3000 °C) and ultra-fast quenching process exhibited ultra-stable chainmail-like particle surface, which endowed the catalyst with high catalytic stability within 300 h of experimental determination. This work provided a new alternative strategy and method for the design of high activity and high stability catalysts.