Combining structure design and surface modification of BPO4 solid acid catalyst to boost the anti-coking performance in dehydration reaction of glycerol

Catalytic vapor-phase dehydration of glycerol is an energy-efficient and environmentally friendly route for producing acrolein, a valuable organic chemical intermediate. However, anti-coking is one of the key problems due to the excessively acid catalytic sites and sluggish mass transfer, restricting the industrial application of this reaction. Herein, potassium element modified BPO4 monolithic foams with the hierarchically porous structure were synthesized by adding potassium element in the gel precursor of BPO4. The catalyst introducing 3% K exhibited the best acrolein selectivity of 81.0% with nearly complete glycerol conversion. In a 10-hour run of the reaction at 320 °C, the selectivity of acrolein could remain at 75.9% with 94.5% glycerol conversion, indicating the superior stability. The excellent activity and stability for 3% K-BPO4 is mainly attributed to the synergetic effect between hierarchical structure providing favorable mass transfer and appropriate acid catalytic sites inhibiting over dehydration reaction. They not only boost activity but also reduce coking, providing a unique approach for the design of solid acid catalyst.