Under-coordinated AlF3 clusters confined in carbon matrix with robust sintering resistance for dehydrofluorination of hydrofluorocarbons

Abstract

The development of catalysts for the resource utilization of potent greenhouse gases, hydrofluorocarbons (HFCs) by catalytic pyrolysis is of great significance to alleviate the greenhouse effect. Fabricating small catalyst particles with high specific surface area leading to more Lewis acid sites is the effective strategies to achieve highly functional catalysts. However, catalysts tend to sinter at elevated temperatures. Herein, we synthesized carbon matrix confined Al2O3 clusters via the calcination of MIL-53-Al under N2 atmosphere. Then the Al2O3 clusters were in situ fluorinated and turned into AlF3 clusters accordingly. The derived carbon confined AlF3 clusters exhibited outstanding sintering resistance even following thermal treatment at 600 °C. Moreover, the carbon confined AlF3 clusters presented superior catalytic performance for 1,1-difluoroethane (HFC-152a) conversion with near 40% higher than that of AlF3 prepared by traditional precipitation. The excellent catalytic activity and stability were mainly ascribed to the abundant under-coordinated Al species with strong interaction with carbon matrix and high specific surface area. Thus, in this paper, we developed new practicable method to synthesize highly efficient Lewis acid catalysts with strong sintering resistance and abundant acid sites.