Selective oxidation of cellulose into formic acid over heteropolyacid-based temperature responsive catalysts

Formic acid (FA) is one of the most promising vectors for sustainable hydrogen energy and it can be synthesized from renewable biomass resources . In this work, a range of heteropolyacid derived temperature-responsive catalysts (Ch n H 4-n PMo 11 VO 40 , n=1–3) were prepared by modifying H 3 PMo 12 O 40 heteropolyacid with an oxidation site V 5+ and temperature-responsive monomer choline chloride (Ch + ), and used for the cascade conversion of biomass derived cellulose into FA via hydrolysis-oxidation in water. The ChH 3 PMo 11 VO 40 with a Ch/H ratio of 1/3 exhibited an outstanding catalytic performance to give a 49.5% yield of FA at 165 °C after 3 h reaction time. Catalytic activity of Ch n H 4-n PMo 11 VO 40 was found to be related to its amount of H + and V 5+ , while the recyclable ability of Ch n H 4-n PMo 11 VO 40 was found to be related to its amount of Ch + . The as-prepared catalyst could be perfectly recycled with a single decrease the temperature of reaction systems, and be reused four times with limit loss in catalytic activity. The developed temperature-responsive catalysts have both advantages of homogeneous catalyst and heterogeneous catalyst , which should have potential application in other reactions of lignocellulosic biomass valorization.