Water-Assisted Selective Hydrodeoxygenation of Guaiacol to Cyclohexanol over Supported Ni and Co Bimetallic Catalysts

Hydrodeoxygenation (HDO) of guaiacol, a typical lignin-derived phenolic compound, at relatively mild conditions was studied over γ-Al₂O₃ and ZSM-5 supported catalysts with Ni and/or Co as active metal. Among various catalysts, NiCo/γ-Al₂O₃ catalysts exhibited better guaiacol conversion up to 96.1% with cyclohexanol as the main product in aqueous, due to the proper acidity and interaction between metal particles and support. The effects of process parameters on guaiacol conversion and product distribution were investigated in detail associated with solvent effect. The cleavage of C–O bonds in guaiacol was investigated over NiCo/γ-Al₂O₃ catalysts in aqueous phase. Phenol was found as the main intermediate with 1-methyl-1,2-cyclohexanediol as another intermediate instead of 2-methoxy-cyclohexanol. The demethoxylation first happened to form phenol, and then, the aromatic ring was hydrogenated to give cyclohexanol after further hydrogenation of cyclohexanone

An Insight into the Selective Conversion of Bamboo Biomass to Ethyl Glycosides

Selective conversion of lignocellulosic biomass to ethyl glycosides and other valued chemicals is an important step for biomass utilization. In this paper, directional liquefaction of bamboo biomass into ethyl glucosides and ethyl xylosides with acid in ethanol media was investigated. The ethyl glycoside distribution was found to depend mainly on the temperature and the amount of H₂SO₄. Under a shorter reaction time of 30 min at a temperature of 180 °C, the maximum yield of ethyl glycoside and its derivatives was 40.86 wt % based on raw materials, with 16.07 wt % ethyl glucosides and 10.11 wt % ethyl xylosides, respectively. Additional studies with glucose and xylose as substrates have been conducted under temperatures of 100–200 °C. Ethyl glucosides (xylosides) isomers were favorable during the directional liquefaction process. The quantification of the separated content of ethyl glucosides and ethyl xylosides provides a new paradigm for the use of biomass as a raw material for renewable energy and chemical industries

Mixed Plastics Wastes Upcycling with High-Stability Single-Atom Ru Catalyst

Mixed plastic waste treatment has long been a significant challenge due to complex composition and sorting costs. In this study, we have achieved a breakthrough in converting mixed plastic wastes into a single chemical product using our innovative single-atom catalysts for the first time. The single-atom Ru catalyst can convert ∼90% of real mixed plastic wastes into methane products (selectivity >99%). The unique electronic structure of Ru sites regulates the adsorption energy of mixed plastic intermediates, leading to rapid decomposition of mixed plastics and superior cycle stability compared to traditional nanocatalysts. The global warming potential of the entire process was evaluated. Our proposed carbon-reducing process utilizing single-atom catalysts launches a new era of mixed plastic waste valorization