整体式除氚催化剂的制备及催化氧化性能  

Preparation of Monolithic Catalyst and Its Catalytic Oxidation Performance for Detritiation Technology

作　　者：肖超[1] 杨勇[1] 陈志林[1] XIAO Chao;YANG Yong;CHEN Zhi-lin(Institute of Nuclear Physics and Chemistry,China Academy of Engineering Physics,Mianyang 621900,China)

机构地区：[1]中国工程物理研究院核物理与化学研究所,四川绵阳621900

出　　处：《核化学与放射化学》2021年第3期286-290,共5页Journal of Nuclear and Radiochemistry

摘　　要：针对大型核设施产生的大流量废气的处理,发展低气阻的整体式催化剂尤为必要。本工作在整体式堇青石载体上生长分子筛涂层,以离子交换法负载活性组分Pt,获得的整体式催化剂具有高的金属分散度,达到了60%。使用该催化剂,在15℃、体积空速为10000~40000 h^(-1)、1.0%(体积分数)H_(2)的条件下实现大于99.9%的H_(2)转化率;在25℃、体积空速为50000 h^(-1)、1.0%H_(2)的条件下实现H_(2)的完全转化。在更低的H_(2)浓度下(0.1%H_(2)和0.5%H_(2)),该催化剂在湿条件下的H_(2)转化率低于干条件下的H_(2)转化率,表明水蒸气会抑制室温催化活性。由于分子筛涂层较Al_(2)O_(3)涂层具有更低的吸水性,整体式Pt/sil-cord催化剂在湿条件下具有比Pt/Al_(2)O_(3)高得多的室温催化活性(0.1%H_(2)下,转化率为80%,而在Pt/Al_(2)O_(3)上的转化率为13%),表现出较好的抗湿性。Development of monolithic catalyst is vital for the treatment of high flow exhaust gas generated in large nuclear facilities.Herein,a new method including zeolite washcoat growth on cordierite monolith followed by ion exchange of Pt was reported.The obtained monolithic Pt/zeolite catalyst possesses high metal dispersion(60%).At 15℃and 1.0%H_(2),a conversion of>99.9%is achieved with a gas hourly space velocity(GHSV)of 10000-40000 h^(-1)over the monolithic Pt catalyst,and complete conversion is achieved with a GHSV of 50000 h^(-1)at 25℃and 1.0%H_(2).At 0.1%H_(2)and 0.5%H_(2),the catalytic activity is lower in wet conditions than that in dry conditions because the water vapor can inhibit the room temperature catalytic activity.Since the zeolite coating has lower water absorption capacity than Al_(2)O_(3),the hydrogen conversion over monolithic Pt/sil-cord remains 80%at 0.1%H_(2)while the conversion over monolithic Pt/Al_(2)O_(3)is only 13%.Thus the monolithic Pt/zeolite catalyst shows obvious steam-tolerance.

关 键 词：催化氧化 整体式催化剂 除氚技术 氚辐射防护 

分 类 号：O643.3[理学—物理化学]