Catalytic Aerobic Oxidation Of Ethyl Lactate To Ethyl Pyruvate Over Metal-Organic Frameworks-Derived Carbon-Supported Vanadium Catalysts

The over-exploitation and utilization of fossil energy makes the fossil energy reserves in today’s world in short supply,and the over-consumption of increasingly exhausted non-renewable energy has caused very serious environmental problems,which has forced researchers to try renewabled energy to produce fuels and value-added chemicals.Biomass,as an abundant renewable organic carbon source,has attracted significant attention in last decade and can be converted into many valuable chemicals.Lactic acid is a highly attractive biomass-derived chemical,which can be further converted into value-added products through chemical/biological ways,such as,acrylic acid,pyruvic acid,polylactic acid,1,2-propanediol etc.Among them,pyruvic acid can be used to prepare various industrial products such as perfumes,food additives,medicines and electronic materials,and it can also be used as raw materials for various bioactive substances such as antiviral and anticancer drugs.The production of pyruvic acid from lactic acid recently received significant attention from researchers due to the excellent atomic efficiency.Metal-organic frameworks（MOFs）are highly appealing materials in last decade due to the highly diversified structure,high specific surface area,and adjustable pore size.It’s also a promising precursor to prepare active catalysts or supports.In this work,a variety of metal-organic frameworks（MOFs）were used as the precursor to prepare vanadium catalys to catalyze aerobic oxidation of ethyl lactate（EL）to ethyl pyruvate（EP）.The carbon support obtained by pyrolysis of MOF-5 at 1000^°C was the best material after supporting vanadium at 130^°C in 6 h,95.72%conversion of ethyl lactate and 67.10%selectivity of ethyl pyruvate could be obtained.The catalytic performance of the catalyst remained unchanged after 5th cycles,demonstrating the good stability.Through characeterization techniques such as XRD,ICP-AES,XPS,BET and the stability test,the ratio of V⁵⁺/V⁴⁺species,instead of pore structure,significantly influence the catalytic performance of the V catalyst.