锰改性对ZIF-67衍生Co_(3)O_(4)低温催化氧化甲醛性能的影响  

Effect of manganese modification on the low-temperature formaldehyde oxidation performance of ZIF-67 derived Co_(3)O_(4)

作　　者：向宁 韩小金[2] 郑剑锋[2] 李巧艳 赵青松 侯亚芹[2] 黄张根[2] XIANG Ning;HAN Xiao-jin;ZHENG Jian-feng;LI Qiao-yan;ZHAO Qing-song;HOU Ya-qin;HUANG Zhang-gen(Department of Life Sciences,Changzhi University,Changzhi 046011,China;State Key Laboratory of Coal Conversion,Institute of Coal Chemistry,Chinese Academy of Sciences,Taiyuan 030001,China;College of Environmental Science and Engineering,Taiyuan University of Technology,Jinzhong 030600,China)

机构地区：[1]长治学院生命科学系,山西长治046011 [2]中国科学院山西煤炭化学研究所煤转化国家重点实验室,山西太原030001 [3]太原理工大学环境科学与工程学院,山西晋中030600

出　　处：《燃料化学学报》2022年第7期859-867,共9页Journal of Fuel Chemistry and Technology

基　　金：国家自然科学基金(21978314);山西省高等学校科技创新项目(2021L527);山西省“1331”工程资助。

摘　　要：针对ZIF-67衍生Co_(3)O_(4)催化剂低温甲醛氧化性能不佳的问题,采用锰(Mn)对Co_(3)O_(4)催化剂进行改性以提升其低温甲醛氧化性能。活性评价结果表明,相比于未改性的Co_(3)O_(4)催化剂,Mn改性后的Mn-Co_(3)O_(4)催化剂甲醛氧化活性显著提升,在118℃下即可实现90%的甲醛转化率(进口甲醛浓度为98.16 mg/m^(3),空速为60000 mL/(gcat·h))。XRD、Raman和BET结果显示,Mn改性后催化剂的结晶度降低,缺陷增加,比表面积增大,这有利于反应物分子的吸附和活性位点的暴露。XPS、H_(2)-TPR和O_(2)-TPD表征结果表明,Mn-Co间存在的强相互作用显著改善了Mn-Co_(3)O_(4)催化剂的低温氧化还原性能和氧活化能力,使其具有更加丰富的Co^(3+)和表面吸附氧物种。最终,这些因素共同促进了Mn-Co_(3)O_(4)催化剂对甲醛的降解。此外,in-situ DRIFTS结果表明,亚甲二氧基和甲酸盐物种是甲醛在Mn-Co_(3)O_(4)催化剂上催化氧化的主要中间物种。In consideration of the inferior performance of ZIF-67 derived Co_(3)O_(4)catalyst in the low-temperature formaldehyde oxidation,manganese was utilized to modify Co_(3)O_(4)catalyst.The results showed that the Mn-Co_(3)O_(4)catalyst exhibited the superior HCHO oxidation activity and achieved 90%HCHO conversion at a WHSV of 60000 mL/(gcat·h)and inlet HCHO concentration of 98.16 mg/m^(3) at 118℃.XRD,Raman and BET results demonstrated that the Mn-Co_(3)O_(4)catalyst possessed lower crystallinity,more defects and specific surface area,which was conducive to the adsorption of reactants and exposure of more active sites.XPS,H_(2)-TPR and O_(2)-TPD results indicated that the strong interaction between Mn and Co species prominently improved the low temperature reducibility and O_(2)activation performance of Mn-Co_(3)O_(4)catalyst,which endowed it with more abundant Co^(3+) and surface-adsorbed oxygen species.Therefore,the Mn-Co_(3)O_(4)catalyst exhibited superior HCHO oxidation performance.Based on in-situ DRIFTS results,dioxymethylene and formate species were recognized as the main reaction intermediates of HCHO oxidation over the Mn-Co_(3)O_(4)catalyst.

关 键 词：甲醛 催化氧化 ZIF-67 锰钴氧化物 

分 类 号：X701.7[环境科学与工程—环境工程]