Mesoporous Siliconiobium Phosphate as a Pure Brønsted Acid Catalyst with Excellent Performance for the Dehydration of Glycerol to Acrolein

Abstract The development of solid acid catalysts that contain a high density of Brønsted acid sites with suitable acidity, as well as a long lifetime, is one of great challenges for the efficient dehydration of glycerol to acrolein. Herein, we report on a mesoporous siliconiobium phosphate (NbPSi‐0.5) composite, which is a promising solid Brønsted acid that is a potential candidate for such a high‐performance catalyst. A variety of characterization results confirm that NbPSi‐0.5 contains nearly pure Brønsted acid sites and has well‐defined large mesopores. In addition, NbPSi‐0.5 contains a similar amount of acid sites and exhibits weaker acidity than that of the highly acidic niobium phosphate and HZSM‐5 zeolite. NbPSi‐0.5 is quite stable and has a high activity for the dehydration of glycerol. The stability of NbPSi‐0.5 is about three times higher than that of the reported catalyst. The significantly enhanced catalytic performance of NbPSi‐0.5 can be attributed to 1) nearly pure Brønsted acidity, which suppresses side reactions that lead to coke formation; 2) a significant reduction of pore blocking due to the mesopores; and 3) a decrease in the amount and oxidation temperature of coke.