Catalytic hydrogenolysis of lignin with NiO-CuO catalyst via alcohol-water coprecipitation

Abstract

Using lignin to produce valuable chemicals can help reduce reliance on fossil fuels. The NiO catalyst prepared by alcohol/water co-precipitation method showed higher activity than NiO prepared by ammonia-water precipitation method in catalytic hydrogenolysis (CH) reaction of enzymatic hydrolysis lignin (EHL). The yield of lignin oil reached 85.68 % at 270 °C for 30 min. The catalytic performance was further improved by the introduction of CuO. Under the optimized conditions (290 °C, 120 min), the yield of lignin oil was up to 95.13 % using N-C (4:1) as the catalyst. The GC-MS analysis showed that the lignin oil mainly consisted of phenols, esters, hydrocarbons, and other oxygenated compounds, among which, the phenolic content was up to 57.90 %. These results indicate that the prepared catalyst can effectively break the C-O and C-C bonds in lignin and significantly promote the formation of phenolics.