X射线光电子能谱与^(13)C核磁共振在生物质碳表征中的应用  

Characterization of Biochar by X-Ray Photoelectron Spectroscopy and ^(13)C Nuclear Magnetic Resonance

作　　者：徐东昱[1] 金洁[1] 颜钰[1] 韩兰芳 康明洁 王子莹[1] 赵烨[1] 孙可[1] 

机构地区：[1]北京师范大学环境学院水环境模拟国家重点实验室,北京100875

出　　处：《光谱学与光谱分析》2014年第12期3415-3418,共4页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金面上基金项目(41273106);教育部新世纪优秀人才支持计划项目(NCET-09-0233)资助

摘　　要：近年来,生物质碳(biochar)作为新型吸附剂被广泛研究。但由于制备biochar的生物质原料和热解温度的不同,使biochar的结构和组成存在差异,从而影响其对污染物的吸附。目前关于biochar的结构和组成的研究还不够全面。因此,结合了能谱与光谱分析的手段,对biochar的结构和组成进行了深入的分析。选取木质类(柳树枝条)和草类(水稻秸秆)作为原料,分别在不同热解温度(300,450和600℃)下制得biochars,并对biochars样品进行元素分析、X射线光电子能谱分析(XPS)和固态13 C核磁共振(13 C NMR)研究,以阐明不同热解温度和生物质来源的biochars的结构和组成。结果显示:biochar的H/C,O/C和(O+N)/C的比值随着热解温度的升高而降低;草类biochar比木质类biochar具有更高的灰分含量和表面极性;木质类biochar的矿物主要分布在样品颗粒内部,其表面被有机质覆盖,而草类biochar部分矿物暴露在样品颗粒表面;13 C NMR显示低温制得的biochar主要由芳香碳、脂肪碳、羧基和羰基碳组成,高温制得的biochar主要由芳香碳组成,且低温制得biochars中,木质类biochars比草类biochars含有更高的木质素的残留碳结构,这是由于木质类biochars原材料中含有更高的木质素。The wood（willow branch）and grass（rice straw）materials were pyrolyzed at different temperatures（300,450 and 600 ℃）to obtain the biochars used in the present study.The biochars were characterized using elementary analysis,X-ray photoelectron spectroscopy（XPS）and solid state ^13 C cross-polarization and magic angle spinning nuclear magnetic resonance spectroscopy（^13 C NMR）to illuminate the structure and composition of the biochars which were derived from the different thermal temperatures and biomass.The results showed that the H/C,O/C and（O＋N）/C ratios of the biochars decreased with the increase in the pyrolysis temperatures.The surface polarity and ash content of the grass-derived biochars were higher than those of the wood-derived biochars.The minerals of the wood-derived biochars were mainly covered by the organic matter;in contrast,parts of the mineral surfaces of the grass-derived biochars were not covered by organic matter.The ^13 C NMR of the low temperature-derived biochars revealed a large contribution of aromatic carbon,aliphatic carbon,carboxyl and carbonyl carbon,while the high temperature-derived biochars contained a large amount of aromatic carbon.Moreover,the wood-derived biochars produced at low heat treatment temperatures contained more lignin residues than grass-derived ones,probably due to the existence of high lignin content in the feedstock soures of wood-derived biochars.The results of the study would be useful for environmental application of biochars.

关 键 词：生物质碳 元素分析 X射线光电子能谱 固态^13 C核磁共振 

分 类 号：O657.3[理学—分析化学]