摘要
在对酶解木质素以及尿素、三聚氰胺改性木质素的热解过程、木质素基炭的化学结构和微观结构等系列研究基础上,采用木质素改性、炭化和氨气活化等过程制备了木质素基活性炭,运用氮气吸附法、傅里叶变换红外光谱、X射线光电子能谱和电化学等方法分析了木质素基活性炭的孔隙结构、表面化学结构与电催化氧气还原反应(ORR)的催化性能。研究结果表明:以酶解木质素为原料,通过含氮化合物改性、炭化和高温氨气活化能够制备出ORR电催化性能优良的木质素基活性炭。采用含氮化合物改性和氨气活化的方法,可以有效调控木质素基活性炭的孔隙结构,以及吡啶氮(N-6)、吡咯氮(N-5)和季氮(N-Q)等含氮基团含量,从而达到调控木质素基活性炭的ORR电催化性能的目的。木质素经三聚氰胺改性、800℃炭化、950℃氨气活化制得的活性炭L-M-800-NH_(3)-950比表面积为1304 m^(2)/g,微孔(0.438 cm^(3)/g)和中孔(0.302 cm^(3)/g)结构发达,含氮量为6.82%,季氮基团为64.8%,电催化性能与商业20%Pt/C材料接近。
Lignin-based activated carbons were prepared by the consecutive procedure of lignin modification,carbonization and ammonia activation using enzymatic hydrolysis lignin as starting material,in terms of our serial investigations that have been conducted on pyrolysis of starting materials,surface chemistry and microstructure of lignin-derived chars.Nitrogen adsorption,Fourier transform infrared spectroscopy,X-ray photoelectron spectroscopy and electronic chemistry methods were employed to characterize the pore structure and surface chemistry of lignin-based activated carbons and to evaluate the catalytic performance as electrocatalysts for oxygen reduction reaction(ORR).The results showed that lignin-based activated carbons with good performance of electronically catalyzing ORR could be obtained through nitrogen-containing chemicals modification of enzymatic hydrolysis lignin followed by carbonization and ammonia activation.By combing the method of lignin modification with nitrogen-containing substances and ammonia activation,the pore structure and the concentration of nitrogen-containing groups including pyridine-like,pyrrole-like and quaternary-like species could be tuned and,as a result,benefit to regulate the electrocatalytic properties of lignin-based activated carbons.Using melamine-modified enzymatic hydrolysis lignin as starting material produced the lignin-based activated carbons with a comparable electrocatalytic performance with commercially available 20%Pt/C catalyst,which possess a surface areas of more than 1300 m^(2)/g,developed microporosity and mesoporisty,a nitrogen content of more than 6%and a high concentration of quaternary-like groups.
作者
金凯楠
左宋林
桂有才
申保收
王珊珊
崔难难
JIN Kainan;ZUO Songlin;GUI Youcai;SHEN Baoshou;WANG Shanshan;CUI Nannan(College of Chemical Engineering,Nanjing Forestry University,Nanjing 210037,China;Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity,Xi'an 710127,China;College of Urban and Environmental Sciences/Institute of Earth Surface System and Hazards,Northwest University,Xi'an 710127,China)
出处
《林产化学与工业》
CAS
CSCD
北大核心
2021年第6期27-35,共9页
Chemistry and Industry of Forest Products
基金
国家重点研发计划资助项目(2019YFB1503804)
江苏省自然科学基金青年项目(BK20170928)。
关键词
木质素
活性炭
电催化
氧气还原
三聚氰胺
lignin
activated carbon
electrocatalysis
oxygen reduction reaction
melamine
