Synthesis of C2 oxygenates from syngas over Rh–Mn–Li/SiO2 catalysts: effect of supports prepared using different ammonia concentrations

Abstract

The effects of surface properties of the monodispersed SiO₂ prepared using different ammonia concentrations on the catalytic performance of Rh–Mn–Li/SiO₂ for CO hydrogenation to C₂ oxygenates were investigated. The investigation based on the catalytic performance and characterizations of the catalysts suggested that the catalytic performance was relatively stable on the Rh–Mn–Li catalyst supported on the SiO₂ prepared using high ammonia concentration, which is attributed to the steady state of the metals supported on it. However, the rough surface of SiO₂ prepared using a low ammonia concentration resulted in easy agglomeration of the metals. Correspondingly, the size of Rh particles increased and the isolated Rh⁺ sites decreased in the reaction process, leading to the decrease of C₂ oxygenate selectivity of the catalyst as a function of time.