Phosphorus-modified zirconium metal organic frameworks for catalytic transfer hydrogenation of furfural

Phosphorus-modified Zr-metal organic framework (P/Zr-MOF) catalysts were synthesized by a (NH4)2HPO4 pyrolysis approach starting from Zr-MOFs. The furfural catalytic transfer hydrogenation performance of P/Zr-MOFs was studied with i-propanol as a hydrogen donor. Experimental results show that the furfural conversion of P/Zr-MOFs rose from 59.1% to 96.1% compared with that of Zr-MOFs. In P/Zr-MOFs compared with Zr-MOFs, a part of O–Zr–O in the MOFs was phosphated to form O–Zr–P and P–Zr–P, in which Zr–P possessed stronger Lewis acidity and basicity than Zr–O, which is favorable for hexatomic ring-catalytic reactions. Hence, P/Zr-MOFs exhibited higher Meerwein–Ponndorf–Verley reactivity. Based on this result, a plausible mechanism of catalytic modification was proposed.