摘要
制备方法会影响催化剂中Cu物种种类、分散性及其与载体之间的相互作用。分别采用沉积沉淀法、氨蒸法、浸渍法和共沉淀法制备了以Ce_(0.8)Zr_(0.2)O_(2)固溶体为载体、Cu负载量(质量分数)为15%的Cu/Ce_(0.8)Zr_(0.2)O_(2)催化剂。采用XRD、N_(2)物理吸/脱附、N_(2)O滴定和SEM等对催化剂的物相组成、织构性质、Cu分散度和微观结构等进行了表征,并采用固定床反应器评价了催化剂的甲醇水蒸气重整制氢催化性能。结果表明,与其他3种方法制备的Cu/Ce_(0.8)Zr_(0.2)O_(2)催化剂相比,采用沉积沉淀法制备的Cu/Ce_(0.8)Zr_(0.2)O_(2)催化剂(Cu/Ce_(0.8)Zr_(0.2)O_(2)-DP)具有相对最大的比表面积(82.5 m^(2)/g)和Cu比表面积(206.0 m^(2)/g),以及相对最高的Cu分散度(30.5%)。在温度为250℃、常压、n(去离子水):n(甲醇)为1.3:1.0和液时空速为6 mL/(g·h)的条件下反应24 h,Cu/Ce_(0.8)Zr_(0.2)O_(2)-DP表现出相对最优的催化性能,其甲醇转化率为95.2%,产氢速率为286.8 mmol/(g·h),CO选择性为0.86%。
The preparation methods can affect the type and dispersion of Cu species,as well as the interaction between Cu species and supports in catalysts.Cu/Ce_(0.8)Zr_(0.2)O_(2) catalysts with Ce_(0.8)Zr_(0.2)O_(2) sosolid as the support and Cu loading(mass fraction) of 15% were prepared by deposition precipitation,ammonia evaporation,impregnation and co-precipitation methods,respectively.The phase compositions,texture properties,Cu dispersions and microstructures of the catalysts were characterized by XRD,N_(2) physical adsorption/desorption,N_(2O) titration,SEM,etc.And the catalytic performances of the catalysts for methanol steam reforming to produce hydrogen were evaluated in a fixed-bed reactor.The results show that compared with the Cu/Ce_(0.8)Zr_(0.2)O_(2) catalysts prepared by another three methods,the Cu/Ce_(0.8)Zr_(0.2)O_(2) catalyst(Cu/Ce_(0.8)Zr_(0.2)O_2-DP) prepared by deposition precipitation method has the largest specific surface area(82.5 m^(2)/g) and Cu specific surface area(206.0 m^(2)/g),as well as the highest Cu dispersion(30.5%).Under the reaction conditions of 250 ℃,atmospheric pressure,n(deionized water):n(methanol) of 1.3:1.0 and liquid space velocity of 6 mL/(g·h) for 24 h,Cu/Ce_(0.8)Zr_(0.2)O_2-DP shows relatively optimal catalytic performance with methanol conversion rate of 95.2%,hydrogen production rate of 286.8 mmol/(g·h) and CO selectivity of 0.86%.
作者
徐青文
柯举仓
李蕊
李鹏
王凤霞
马清祥
赵天生
XU Qingwen;KE Jucang;LI Rui;LI Peng;WANG Fengxia;MA Qingxiang;ZHAO Tiansheng(State Key Laboratory of High-Efficiency Utilization of Coal and Green Chemical Engineering,College of Chemistry and Chemical Engineering,Ningxia University,Yinchuan 750021,Ningxia,China;Analysis and Testing Center,Ningxia University,Yinchuan 750021,Ningxia,China)
出处
《低碳化学与化工》
CAS
北大核心
2024年第9期33-40,50,共9页
Low-Carbon Chemistry and Chemical Engineering
基金
宁夏自然科学基金(2021AAC03108)。
关键词
甲醇水蒸气重整
Cu基催化剂
制备方法
铈锆固溶体
Cu分散度
methanol steam reforming
Cu-based catalysts
preparation methods
cerium-zirconium sosolid
Cu dispersion
