纳米多孔钌催化纤维素高效转化制备甲烷

Highly Efficient Conversion of Cellulose into Methane over Nanoporous Ru Catalyst

摘要:

高效利用纤维素制备燃料甲烷对人类社会的可持续发展具有重要意义。本文采用纳米多孔钌催化剂，在相对温和的反应条件（220 °C、初始0.5 MPa氢气压力）下反应8 h，纤维素转化率为75.8%，甲烷选择性达到82.2%。催化剂可以循环套用10次，甲烷收率最高可达79.5%。研究了纤维素的转化历程和反应前后纤维素结构变化，发现纤维素制备甲烷反应分为酸催化的水解过程和纳米多孔钌催化的加氢过程两个阶段。因此，设计使用钼、钨、铼和钒元素作为Brønsted酸中心对纳米多孔钌进行改性。由此设计合成的纳米多孔钌双功能催化体系可以提高纤维素向甲烷转化的整体反应速率，甲烷收率提高了9.6%。

Abstract:

The efficient utilization of cellulose for producing methane fuel is of great significance to the sustainable development of human society. In this article, nanoporous Ru catalyst was employed for the transformation of cellulose to methane under the relatively mild conditions of 220 °C and initial H2 pressure 0.5 MPa, and the conversion of cellulose is 75.8% with 82.2% selectivity of methane using H2O as solvent. The catalyst was reused for 10 times, and the highest yield of CH4 was 79.5%. The reaction mechanism of cellulose transformation and structure change of cellulose in the process were studied. Results showed that cellulose transformation consist of two parts, which are acid-catalyzed hydrolysis process and nanoporous Ru-catalyzed hydrogenation process. Therefore, a bifunctional nanoporous Ru was designed with Brønsted acid sites by Mo, W, Re and V doping. The conversion rate of cellulose was significantly increased and yield of methane increased by 9.6% with the bifunctional nanoporous Ru.