摘要
通过控制苯乙烯的用量制备不同尺寸的聚苯乙烯胶晶模板剂,制备了不同孔径分布的La_(2)FeNiO_(6)双钙钛矿氧化物,表征了其晶体结构、表面形貌、元素价态、孔径分布和还原性能。实验结果表明:不同尺寸的模板剂制备的试样均形成了双钙钛矿结构,孔径为介孔-介孔复合结构;试样中A位La元素为+3价,B位Fe以+3价为主,Ni以+2价为主,孔径分布的差异导致各试样的B位元素价态分布不同,影响其还原性能、氧空位的形成及表面吸附氧的数量。当模板剂的尺寸为250 nm时,制备的La_(2)FeNiO_(6)双钙钛矿氧化物具有较大孔径分布和比表面积,氧空位和表面吸附氧物种较多,在3 MPa、375℃和15 mL/min的氢气流速条件下,将该催化剂用于间甲酚的催化加氢脱氧反应,间甲酚的转化率达到85%,产物以甲苯为主,该催化剂具有良好的抗积碳性能。
Polystyrene colloidal template agents of different sizes were prepared separately by controlling the amount of styrene.Using different sizes of polystyrene colloidal template agents as templates,La_(2)FeNiO_(6)double perovskites oxides with different pore size distributions were prepared.The crystal structure,surface morphology,elemental valence,pore size distribution and reduction properties of La_(2)FeNiO_(6)double perovskites oxides were characterized by XRD,SEM,XPS,TPR and other methods,respectively.The results showed that the samples prepared with different sizes of template agents all formed a double perovskites structure,and the pore size is amesoporous-mesoporous composite structure;the A-site La element has a+3 valence,the B-site Fe mainly has a+3 valence and Ni mainly has a+2 valence in the samples.The difference in pore size distribution leads to different valence distributions of B-site elements in each sample,which affects its reduction performance,the formation of oxygen vacancies,and the amount of adsorbed oxygen on the surface.When the size of the template is 250 nm,the prepared La_(2)FeNiO_(6)double perovskites oxides has a large pore size distribution and specific surface area,with more oxygen vacancies and surface adsorbed oxygen species.At 3 MPa,375℃and 15 mL/min hydrogen flow rate,the catalyst is used for catalytic hydrogenation and deoxidation of m-cresol.The conversion rate of m-cresol reaches 85%,and the direct deoxygenation reaction mainly occurs.The dominated product is toluene,and the catalyst has good resistance to carbon deposition.
作者
陈平清
练彩霞
李凝
蒋武
彭林森
吴俊豪
Chen Pingqing;Lian Caixia;Li Ning;Jiang Wu;Peng Linsen;Wu Junhao(Maoming Vocational and Technical College,Dean’s Office,Maoming 525000,Guangdong,China;Guangdong University of Petrochemical Technology,College of Chemical Engineering,Maoming 525000,Guangdong,China;Xiangtan University,College of Chemical Engineering,Xiangtan 411105,Hu’nan,China)
出处
《精细石油化工》
CAS
2023年第4期31-36,共6页
Speciality Petrochemicals
基金
广东省创强重大项目(2017KZDXM057)。
关键词
介孔-介孔
多级孔
镧
铁
镍
双钙钛矿氧化物
加氢脱氧
meso-mesoporous
multistage pore
lanthanum
iron
nickel
double perovskites oxides
hydrodeoxygenation
