半纤维素是木质纤维素类生物质重要组成部分。每年我国农林加工废弃物所含半纤维素约占2亿吨，高值化利用、转化如此巨大的资源“仓库”对实现生物质转化工艺实用化具有重要意义。基于低聚木糖是生物质炼制路线中半纤维素的主要降解产物之一，本项目拟开展低聚木糖在CO2/H2O介质中高选择性催化加氢制备1,4-戊二醇的研究，设计合成Au-PGM（Pt族贵金属）双金属催化剂，构建用于定向催化转化低聚木糖的双功能组合催化（剂）体系，并保持催化剂在反应过程中的稳定性。研究Au-PGM双金属催化剂与催化活性、目标产物选择性的关联规律，加深对低聚木糖水溶液催化转化反应机理的认识。借助多种催化剂表征手段，正确解析催化剂的结构特征与物理化学性质，理解相关因素对催化剂C=O键和C=C键加氢能力的影响，合成具有选择加氢性能的Au-PGM双金属催化剂。所得结果对于开发高效半纤维素催化转化新体系、新方法具有重要的借鉴意义。

Hemicellulose is an important component of lignocellulosic biomass. The hemicellulose in annual wastes of agroforestry processing is approximately 200 million tons. Transforming and high-value utilization of such a huge resource “warehouse” is significant to the biomass conversion processes. Xylooligosaccharides (XOS) is one of the main products of hemicellulose degradation in biorefinery. In this proposal, with the aim of exploring the key issues in the catalytic conversion of XOS, we attempt to investigate the selective conversion of biomass-derived XOS to 1,4-pentanediol in CO2/H2O system, design and synthesize supported Au-PGM (Platinum Group Metals) bimetallic catalysts, construct an efficient dual catalytic system for the direct catalytic conversion of XOS and maintain the stability of the catalyst during the reaction. The correlation between Au-PGM bimetallic catalyst and catalytic hydrogenation activity and selectivity to the target product will be studied to in-depth understand the mechanism for the direct catalytic conversion of XOS to 1,4-pentanediol. By using various characterization techniques, we will reveal the structural characteristics and adsorption properties of the catalyst, understand the relevant factors that affect the ability for hydrogenating the C=C bond and C=O bond of the catalyst, and rationally synthesize Au-PGM bimetallic catalysts with good performance of selective hydrogenation. The results obtained would be referential for the development of new system and new method for efficient catalytic hemicellulose.