Utilizing Cl coordination to facilitate Ru-Ag self-assembling into alloy and recover thermally-inactivated catalyst for propane combustion

Abstract

The exploit of simple method to synthesize and recover catalyst is meaningful to widespread application of environmental catalysis. Different from traditional knowledge about deposition of Ag cation by Cl anion, we find that Cl anion coordinates with Ru and Ag cations simultaneously to micro-micelles and results in homogeneously alloying of bimetals. The Ru-Ag alloy exhibits a remarkable activity and stability in propane catalytic oxidation at moderate condition, but is still inactivated by extremely-high temperature and humidity due to metal sintering and oxidation as well as support reconstruction. Fortunately, utilization of Cl coordination to extract and combine bimetals at redox condition is proved as a feasible and simple way to regenerate the thermally-inactivated catalyst. With in-situ characterization, the synergic effect between Ru and Ag on propane oxidation obeying Mars-van-Krevelen mechanism is revealed. Through monolith test, the practice application of Ru-Ag catalyst prepared via Cl-assisted method is thought to be promising.