钌基催化剂配位环境对聚乙烯氢解性能的影响  

Effect of coordination environment of ruthenium-based catalysts on their performance for polyethylene hydrogenolysis

作　　者：颜诗宇 高姣姣 杨太顺 谢尚志 杨艳娟 徐晶 YAN Shiyu;GAO Jiaojiao;YANG Taishun;XIE Shangzhi;YANG Yanjuan;XU Jing(Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology,School of Chemistry and Chemical Engineering,Guangxi University,Nanning 530004,Guangxi,China;State Key Laboratory of Green Chemical Engineering and Industrial Catalysis,School of Chemical Engineering,East China University of Science and Technology,Shanghai 200237,China)

机构地区：[1]广西大学化学化工学院,广西石化资源加工与过程强化技术重点实验室,广西南宁530004 [2]华东理工大学化工学院,绿色化工与工业催化全国重点实验室,上海200237

出　　处：《化工学报》2024年第10期3588-3599,共12页CIESC Journal

基　　金：广西科技基地和人才专项(桂科AD23026311);广西科技重大专项(桂科AA23062018)。

摘　　要：聚乙烯氢解可以产生多种碳氢化合物,产品分布非常宽,产物选择性调控具有一定挑战性。通过调控钌负载量制备了不同钌粒径的Ru/CeO_(2)催化剂,利用TEM、insitu DRIFTS和模型计算等多种技术,发现聚乙烯催化氢解的产物分布与钌金属配位环境密切相关。表征和模型计算表明,不同尺寸的钌纳米颗粒具有不同的几何结构和配位环境。钌平均粒径为0.85 nm时,低配位的边/角位点占主导,其C_(2)~C_(40)选择性达到92%。钌平均粒径达到2.75 nm时,高配位的平台位点占主导,C_(2)~C_(40)选择性仅为8%,甲烷选择性高达92%。结合截断六角双锥模型和CO-DRIFTS实验,推断Ru/CeO_(2)催化剂上产物的选择性可能与聚乙烯氢解中间体和钌纳米颗粒表面的相互作用有关,提出了Ru/CeO_(2)催化剂上聚乙烯氢解两种反应路径与配位环境的关系。Polyethylene hydrogenolysis can produce a variety of hydrogen hydride compounds,the product distribution is very wide,and the product selective regulation is challenging.A series of Ru/CeO_(2) catalysts with different Ru particle sizes were prepared by regulating Ru loading.It was observed that the product distribution of polyethylene hydrogenolysis closely correlated with the coordination environments of metal Ru as determined by multiple techniques including TEM,in situ DRIFTS and model calculations.Characterizations and model calculations revealed that Ru nanoparticles with different particle sizes exhibited different metal dispersion,geometric structures and coordination environments.The C_(2)—C_(40) alkanes selectivity of 92%was achieved by using Ru particle sizes with mean diameter of 0.85 nm where the edge/corner sites with low-coordination are dominant.The C_(2)—C_(40) alkanes selectivity of 8%and the methane selectivity of 92%was obtained by using the Ru particle sizes with mean diameter of 2.75 nm where the terrace sites with highly coordinated platform sites are dominate.Combined with truncated hexagonal bipyramid model and CO-DRIFTS experiment,the selectivity of products over Ru/CeO_(2) catalysts was correlated with the interaction between intermediates of polyethylene hydrogenolysis and the surface of Ru nanoparticles.Furthermore,the relation between reaction pathways in polyethylene hydrogenolysis and coordination environments of metal Ru was proposed.

关 键 词：废塑料降解 催化剂 加氢 碳氢化合物 钌纳米颗粒 

分 类 号：TQ426[化学工程]