Atomically dispersed calcium as solid strong base catalyst with high activity and stability  

作　　者：Xiang-Bin Shao Zhi-Wei Xing Si-Yu Liu Ke-Xin Miao Shi-Chao Qi Song-Song Peng Xiao-Qin Liu Lin-Bing Sun 

机构地区：[1]State Key Laboratory of Materials-Oriented Chemical Engineering,Jiangsu National Synergetic Innovation Center for Advanced Materials(SICAM),College of Chemical Engineering,Nanjing Tech University,30 South Puzhu Road,Nanjing,211816,China

出　　处：《Green Energy & Environment》2024年第10期1619-1626,共8页绿色能源与环境（英文版）

基　　金：supported by the National Science Fund for Distinguished Young Scholars(22125804);the National Natural Science Foundation of China(22078155 and 22178163);the National Students'platform for innovation and entrepreneurship training program(20210291013Z).

摘　　要：Solid strong base catalysts are highly attractive for diverse reactions owing to their advantages of neglectable corrosion,facile separation,and environmental friendliness.However,their widespread applications are impeded by basic components aggregation and low stability.In this work,we fabricate single calcium atoms on graphene(denoted as Ca1/G)by use of a redox strategy for the first time,producing solid strong base catalyst with high activity and stability.The precursor Ca(NO_(3))_(2)is first reduced to CaO at 400℃ by the support graphene,forming CaO/G with conventional basic sites,and the subsequent reduction at 850℃results in the generation of Ca1/G with atomically dispersed Ca.Various characterizations reveal that Ca single atoms are anchored on graphene in tetra-coordination(Ca-C_(2)-N_(2))where N is in situ doped from Ca(NO_(3))_(2).The atomically dispersed Ca,along with their anchoring on the support,endow Ca1/G with high activity and stability toward the transesterification reaction of ethylene carbonate with methanol.The turnover frequency value reaches 128.0 h^(-1)on Ca1/G,which is much higher than the traditional counterpart CaO/G and various reported solid strong bases(2.9-46.2 h^(-1)).Moreover,the activity of Ca1/G is well maintained during 5 cycles,while 60%of activity is lost for the conventional analogue CaO/G due to the leaching of Ca.

关 键 词：Solid strong base Single Ca atoms Heterogeneous catalysts TRANSESTERIFICATION REACTION 

分 类 号：O643.36[理学—物理化学]