Catalytic Conversion Of Glucose Into Low Carbon Glycols Over Nano-nickel Catalysts

As renewable and abundant resources, biomass has important practical significance on solving energy crisis and environmental problems. Glucose converts into high value-added polyols, which is considered a potential pathway to effective utilization of biomass. One core of research is to find highly efficient catalyst.The novel, low-cost and remarkable nickel nanoparticles was preparated in this paper. The influence of nickel nanoparticles and WO3 hydrogenolysis glucose was investigated. The main conclusions are as follows:(1)The influence of nickel precursors on catalytic performances of nickel nanoparticles catalysts by hydrazine hydrate method for hydrogenation of glucose to sorbitol was studied. Nickel nanoparticles with different sizes and different structures were prepared by hydrazine hydrate reducing four different precursors, such as nickel chloride, nickel oxalate, nickel acetate, and nickel nitrate. When the nickel chloride was precursor, it could be perpare smallest diameter and highest divergence nickel nanoparticles, subsequently improving catalytic activity. The glucose conversion reached 93.9% with the sorbitol selectivity of 90.1% under the neutral environment.(2) The effects of preparation conditions(such as the dispersants and the pH) on the catalytic activity of nickel nanoparticles catalytic were studied. Compared with citric acid or sodium dodecyl sulfate, sodium dodecyl alkyl group exhibited the best modification effect. Nano-nickel particles were prepared with good dispersity, and optimal activity of glucose hydrogenolysis reaction under pH=10 condition. The glucose conversion and the selectivity of the target products were both increased by optimizing the amount of nano-nickel catalyst.(3) Glucose hydrogenolysis over nickel nanoparticles and WO3 catalysts,result showed good promotion between Ni and WO3. It could improve the overall yield of the target product, especially increased the yield of ethylene glycol. When the mass ratio of nano-nickel and WO3 is 2:1, it showed optimal activity. Through optimizing the operation conditions of hydrogenolysis, glucose conversion reached 92% with the ethylene glycol yield of 30% and the 1, 2-propylene glycol yield of 9.3%. It was aslo find that glucose coking was avoided by reducing its concentration.