Selective Cellulose Hydrogenolysis to Ethanol Using Ni@C Combined with Phosphoric Acid Catalysts

Abstract

Ethanol is an important bulk chemical with diverse applications. Biomass‐derived ethanol is traditionally produced by fermentation. Direct cellulose conversion to ethanol by chemocatalysis is particularly promising but remains a great challenge. Herein, a one‐pot hydrogenolysis of cellulose into ethanol was developed by using graphene‐layers‐encapsulated nickel (Ni@C) catalysts with the aid of H3PO4 in water. The cellulose was hydrolyzed into glucose, which was activated by forming cyclic di‐ester bonds between the OH groups of H3PO4 and glucose, promoting ethanol formation under the synergistic hydrogenation of Ni@C. A 69.1 % yield of ethanol (carbon mole basis) was obtained, which is comparable to the theoretical value achieved by glucose fermentation. An ethanol concentration of up to 8.9 wt % was obtained at an increased cellulose concentration. This work demonstrates a chemocatalytic approach for the high‐yield production of ethanol from renewable cellulosic biomass at high concentration.

Selective Cellulose Hydrogenolysis to 2,5-Hexanedione and 1-Hydroxy-2-hexanone Using Ni@NC Combined with H3PO4

“…Low surface nickel contents were detected in the XPS survey, indicating that after H 2 SO 4 treatment, the survived Ni species were entirely encapsulated by the carbon shells. , As depicted in Figure b, the high solution Ni 2p spectrum could be fitted into metallic Ni and NiO, and the proportion is listed in Table S2. The presence of Ni 0 demonstrated the reduction of Ni 2+ to metallic Ni by the reductive gas such as CO and CH 4 during the annealing process . It was noteworthy that the peak intensity and relative theoretical area ratio of NiO were larger than other nickel species; however, no apparent characteristic peaks of nickel oxide (2θ = 37°) were detected in XRD spectrum, which was possibly because nickel oxide did not manifest detectable signals in XRD result due to its amorphous structure or the limited measurement threshold .…”

Metal-Alkali Catalytic Valorization of Lignocellulose Towards Aromatics and Small Molecular Alcohols and Acids in a Holistic Approach

“…Although the mass oligomers and the component of main monomers are similar with the carbon hydrate products in MgO case under n-butanol/H 2 O (Fig. 4B), MgO has great effect on the selectivity of the monomer carbon hydrate products [15][16][17] . DMF is obtained under 0 and 10 bar pressurized hydrogen, which is ascribed to the hydrogenation and subsequent hydrogenolysis of 5-hydroxymethylfurfural (HMF) produced from catalytic dehydration of cellulose under low hydrogen pressure.…”

“…For example, cellulose and hemicellulose produce high value-added liquid fuels and ne chemicals (liquid fuel oil, food additives and important intermediates such as ethanol, ethylene glycol, hydroxyl ketenes, propylene glycol, glycerol, butanediol, hexadiol, polyol, acetone alcohol, acetone, lactic acid, etc.) [11,[14][15][16][17][18][19][20][21][22] . Lignin, the only renewable aromatic polymer, is showing its signi cant utilization potential for manufacture essence/spice [23][24] , synthesizing valueadded chemicals (dimethyl sulfoxide, alkyl phenol and lubricating oil, etc.)…”

Solvent controlled selective photocatalytic oxidation of benzyl alcohol over Ni@C/TiO2

“…Ni@C was prepared according to the method of Liu [41] . Weigh 0.03 mol of Ni (NO3)•6H2O and citric acid and dissolve them in 20 ml of absolute ethanol.…”