摘要
采用水热法制备了(001)/(101)晶面暴露的TiO_(2)催化剂,对其光催化氧化甘油制备甲酸性能进行了研究。利用SEM、TEM、XRD、XPS、EPR、Raman、UV-vis DRS和PL对TiO_(2)的结构和光学性能进行表征。结果表明,以钛酸异丙酯为Ti源,以氢氟酸为形貌控制剂,通过水热法合成的TiO_(2)暴露出(001)晶面。氢氟酸加入量为2 mL的样品(TiO_(2)-2F)同时暴露锐钛矿(001)和(101)晶面,表现出最高的催化活性和选择性。紫外光照射4 h,TiO_(2)-2F催化剂上甘油转化率为49.0%,甲酸选择性为55.6%。界面接触的(001)和(101)晶面形成表面异质结,抑制光生载流子的复合,提高甘油光催化氧化活性。(001)晶面的氧空位和配位不饱和O_(2c)-Ti_(5c)-O_(2c)键合方式使甘油及其中间产物深度氧化,提高甲酸选择性。机理分析表明,·OH和·O^(-)_(2)是甘油选择性氧化制备甲酸的关键活性物种。
TiO_(2)with different facets were prepared by hydrothermal method for photocatalytic reforming glycerol to formic acid.The structural composition and optical properties of TiO_(2)were characterized by SEM,TEM,XRD,XPS,EPR,Raman,UV-vis DRS and PL.The results showed that TiO_(2)synthesized via hydrothermal method using titanium isopropoxide as Ti source and hydrofluoric acid as morphology control agent exposed(001)crystalline facets.TiO_(2)-2F with 2 mL hydrofluoric acid addition had coexposed anatase(001)and(101)crystalline facets and demonstrated the highest catalytic activity and selectivity.With UV light irradiation for 4 h,the conversion of glycerol over the TiO_(2)-2F catalyst was 49.0%and the formic acid selectivity was 55.6%.The interface-contacted(001)and(101)facets formed surface heterojunctions and improved the activactivity of photocatalytic reforming glycerol to formic acid.(001)facet with oxygen vacancy and coordination unsaturated sites O_(2c)-Ti 5c-O_(2c)caused the deep oxidation of glycerol and its intermediates which improved the selectivity of formic acid.Mechanism analysis showed that·OH and·O^(-)_(2)were the key active species for the selective oxidation of glycerol to formic acid.
作者
侯浩强
杨峥
徐俪菲
马春慧
李伟
罗沙
刘守新
HOU Haoqiang;YANG Zheng;XU Lifei;MA Chunhui;LI Wei;LUO Sha;LIU Shouxin(Key Laboratory of Bio-based Material Science&Technology,Ministry ofEducation,Material Science and Engineering College,Northeast Forestry University,Harbin 150040,China)
出处
《功能材料》
CAS
CSCD
北大核心
2023年第10期10207-10215,共9页
Journal of Functional Materials
基金
国家自然科学基金资助项目(31890773,31971601)
中央高校基本科研业务费专项资金项目(2572021BB12)。
