等离激元共振光转热增强负载纳米金对丁二烯选择性加氢的催化性能

Enhanced Catalytic Performance of Supported Nano-gold by the Localized Surface Plasmon Resonance for Selective Hydrogenation of Butadiene

采用阳离子吸附法制备了氧化石墨烯负载纳米金(Au)催化剂(Au/GO),通过调变Au的负载量(质量分数0.2%~2%),实现了Au在10~21 nm粒径的可控制备.室温下热红外测试显示0.2 W/cm^(2)光照条件下,随着金属负载量和粒径的增加,Au/GO光热温度可升高至110℃,且光热转换效率高达88%.研究发现,以丁二烯的选择性催化加氢作为探针反应,在0.2 W/cm^(2)光照条件下,丁二烯的转化率随Au负载量的增加先升高后降低,丁烯选择性在90%以上;当金负载量为0.5%(颗粒尺寸约15 nm),光热转换温度为100℃时,样品表现出较高的丁二烯转化率(99%)和丁烯选择性(90%),且催化剂经过144 h稳定性测试无失活趋势.与同等条件下的热催化反应相比,光-热驱动的Au/GO的催化活性提高了5倍.原位X射线光电子能谱测试分析表明,Au/GO催化性能的提升主要来源于等离子体光转热过程中激发纳米金表面产生了大量的Au^(δ+)活性位点.

During the polymerization of mono-olefins to prepare polymers,impurities such as alkynes and diolefins can poison the polymerization catalyst.Fossil energy driven thermocatalytic selective hydrogenation is the main impurity removal in the industry,which is a high energy consumption and high pollution process.The development of novel green and low-energy reaction pathways is one of the urgent problems in the current industry.Based on the plasmon resonance effect of metal nanoparticles,converting light energy into thermal energy to drive industrial catalytic hydrogenation is a very promising option.In this study,graphene oxide loaded gold(Au)catalysts(Au/GO)were prepared by cationic adsorption method,and the Au loading(mass fraction 0.2%—2%)was adjusted to achieve controllable preparation of Au in the particle size of 10—21 nm.The efficiency of photo-thermal conversion of Au/GO was as high as 88%.Using the selective catalytic hydrogenation of butadiene as a probe reaction,it was found that under 0.2 W/cm^(2) illumination conditions,the conversion of butadiene increased and then decreased with increasing loading,and the butene selectivity was above 90%.Particularly,Au/GO-0.5 exhibited high butadiene conversion(99%)and butene selectivity(90%)at a gold loading of 0.5%(particle size ca.15 nm)and a photothermal conver⁃sion temperature of 100℃.More importantly,the catalyst showed no deactivation trend after 144 h stability test.In addition,the photo-thermal driven catalytic activity developed in this work was improved by a factor of 5 compared to the thermal catalytic reaction under the same conditions.The analysis by in situ X-ray photoelectron spectroscopy(XPS)tests showed that this improvement in catalytic performance was mainly derived from the large number of Au^(δ+)active sites generated on the excited nanogold surface during the plasma photo-transfer thermal process.This study provides a green and efficient reaction pathway for the selective catalytic hydrogenation of industrial unsaturated olefins.