Enhanced oxidative depolymerization of lignin in cooperative imidazolium-based ionic liquid binary mixtures.

The aerobic oxidation of lignin model 2-phenoxyacetophenone (2-PAP) in cooperative ionic liquid mixtures (CoILs) with 1-ethyl-3-methylimidazolium acetate ([C2C1im]OAc) and 1-benzyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([BZC1im]NTf2) was investigated. Complete degradation of 2-PAP was achieved with [C2C1im]OAc/[BZC1im]NTf2 molar ratio (RIL) of 1/1 and 1/2 at 100 °C for 2 h. The conversion and product yields from CoILs were higher than those in pure ILs, indicating the cooperative effects of [C2C1im]OAc/[BZC1im]NTf2 on cleaving aryl-ether bonds. [C2C1im]OAc promoted the catalytic cleavage of aryl-ether bonds and solvation, and [BZC1im]NTf2 induced the formation of alkyl radicals and enhanced the product selectivity. Accordingly, the highest conversion of alkali lignin (79.8%) was obtained with RIL of 5/1 at 100 °C for 2 h, and phenol monomers (306 mg/g) were selectively produced. The CoILs exhibited good catalytic capacities for oxidative depolymerization of lignin, which strongly depends on the changes in intermolecular interactions and structural organization with varying RIL.

China hotel research: A systematic review of the English language academic literature.

This paper presents the findings of a systematic review performed on 115 academic papers published over a 26-year period from 1984 to 2009 and provides a content analysis of research themes and trends in China hotel research. The findings reveal that hotel management and performance is the theme most frequently examined by researchers, followed by hotel development strategies, and hotel business environment analysis. The analysis also indicates shifts in research methods, trends of publication, journal outlets and authorship information.