多孔碳氮材料负载铜基催化剂用于甲醇氧化羰基化合成碳酸二甲酯的研究  

Copper based catalyst supported on nitrogen hierarcgical porous carbon for oxidative carbonylation of methanol to dimethyl carbonate

作　　者：曹明玉 王庆印[1] 曾毅[1] 王公应[1,2] 白元盛 CAO Mingyu;WANG Qingyin;ZENG Yi;WANG Gongying;BAI Yuansheng(Chengdu Organic Chemistry Co.,Ltd.,Chinese Academy of Sciences,Chengdu 610041,Sichuan,China;National Engineering Laboratory for VOCs Pollution Control Material&Technology,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院成都有机化学有限公司,四川成都610041 [2]中国科学院大学挥发性有机物污染控制材料与技术国家工程实验室,北京100049

出　　处：《天然气化工—C1化学与化工》2022年第4期128-137,共10页Natural Gas Chemical Industry

基　　金：四川省区域创新合作项目(2020YFQ0003);中国科学院2022年西部之光项目。

摘　　要：以纤维素、草酸铵、碳酸氢钠为原料,采用发泡法制备了多孔碳氮材料(NHPC)。以NHPC为载体、CuCl为铜源,采用浸渍法制备了CuCl/NHPC催化剂用于甲醇氧化羰基化合成碳酸二甲酯(DMC),考察了载体、煅烧温度和Cu负载量(质量分数)对催化性能的影响。结果表明,多孔碳材料(HPC)经过草酸铵进行造孔和掺氮后,得到的NHPC比表面积和孔容大幅增加,有利于催化剂中Cu物种的分散和颗粒尺寸缩小,且含氮基团的加入增强了Cu离子和NHPC之间的相互作用,抑制了Cu_(2)(OH)_(3)Cl全部还原为Cu^(0)。以NHPC为载体,Cu负载量为5%时,随着煅烧温度的升高,催化剂中Cu_(2)(OH)_(3)Cl逐渐被还原为低价态的CuCl和单质Cu;其中经300℃煅烧制备的催化剂中Cu^(2+)含量减少,Cu^(+)和Cu^(0)含量增加,在3种Cu物种的协同作用下,催化剂的催化活性最好,此时甲醇转化率、DMC选择性和时空产率分别为13.4%、94.8%和18.8 g/(g·h)。Using cellulose,ammonium oxalate and sodium bicarbonate as raw materials,nitrogen hierarchical porous carbon(NHPC)was prepared by foaming method.Then CuCl/NHPC catalyst was prepared by impregnation method with NHPC as support and CuCl as copper source for oxidative carbonylation of methanol to dimethyl carbonate(DMC).The effects of support,calcination temperature and CuCl loading(mass fraction)on the catalytic performance were investigated.The results show that the specific surface area and pore volume of NHPC obtained from porous carbon material(HPC)after pore forming and nitrogen doping with ammonium oxalate increase greatly,which is conducive to the dispersion of Cu species and the reduction of particle size in the catalyst,and the addition of nitrogen-containing groups enhance the interaction between Cu ions and NHPC and inhibit the complete reduction of Cu_(2)(OH)_(3)Cl to Cu^(0).With NHPC as the support,when the Cu loading is 5%,Cu_(2)(OH)_(3)Cl in the catalyst is gradually reduced to low valence CuCl and elemental Cu with the increase of calcination temperature.Among them,the content of Cu^(2+)in the catalyst calcined at 300℃ decreases,and the content of Cu^(+)and Cu^(0) increases.Under the synergistic action of three Cu species,the catalytic activity of the catalyst is the best.At this time,the methanol conversion,DMC selectivity and space-time yield of the best catalyst are 13.4%,94.8%and 18.8 g/(g·h),respectively.

关 键 词：甲醇 碳酸二甲酯 铜基催化剂 多孔碳氮材料 催化活性 

分 类 号：TQ426[化学工程] TQ225.52[理学—物理化学] O643.3[理学—化学]