Novel mesoporous submicron SO42−/FeCu-ZrO2 catalyst for highly selective liquid-phase nitration of 1-nitronaphthalene with NO2 to 1, 5-dinitronaphthalene under mild conditions

An efficient approach for highly selective preparation of 1,5-dinitronaphthalene from liquid-phase nitration of 1-nitronaphthalene with NO2 over mesoporous submicron sub-SO42−/Fe1.5Cu0.5-ZrO2 (s-SFCZ) superacid catalyst prepared by the two-step hydrothermal impregnation (THI) method has been developed. The results showed that the enhanced 1-nitronaphthalene conversion and 1,5-dinitronaphthalene selectivity were attributed to the synergistic catalysis of s-SFCZ combined O2-Ac2O. 94.8% of 1-nitronaphthalene conversion and 62.1% 1,5-dinitronaphthalene selectivity were achieved under optimal conditions. The characterization results unveiled that s-SFCZ had a uniform morphology, lower nano-crystallite size along with more number of accessible acid sites as compared to SO42−/Fe1.5Cu0.5-ZrO2 (SFCZ) and SO42−/Fe1.5Cu0.5/ZrO2 (SFC/Z) catalysts prepared by conventional methods. Furthermore, the density functional theory calculation revealed the cause of the favorable selectivity to 1,5-dinitronaphthalene in NO2-O2-Ac2O compares to HNO3 system. This work affords a novel strategy for preparing mesoporous submicron catalyst used in the nitration of 1-nitronaphthalene with NO2 to 1,5-dinitronaphthalene, and has potential application prospects.