基于原位红外PCMW2D和2D-COS研究碱/碱土金属对纤维素热解的影响

A Study on the Effect of Alkali/Alkaline Earth Metals on Cellulose Pyrolysis by PCMW2D and 2D-COS Analysis of in situ Infrared Spectra

碱/碱土金属催化纤维素热解过程已经受到广泛关注,本文利用原位红外光谱测试手段,引入移动窗口二维相关光谱(PCMW2D),并结合2D-COS分析方法研究了NaCl和MgCl_(2)对纤维素热解过程中焦表面官能团的影响情况,将热解反应分成脱挥发的物理过程和化学反应过程,分析了不同官能团随温度演变情况。结果发现两种盐会破坏O(2)H···O(6)氢键结构,降低反应起始温度;NaCl通过促进开环起到催化作用,而MgCl_(2)则通过促进分子内脱水影响热解过程。

The catalytic effect of alkali/alkaline earth metals during cellulose pyrolysis has received wide attention.In this study,perturbation-correlation moving-window two-dimensional(PCMW2D)correlation spectroscopy was introduced for analyzing the in situ infrared spectra.A combination of PCMW2D and 2D-COS analysis was used to investigate the effect of NaCl and MgCl_(2) on the char functional groups during cellulose pyrolysis..The pyrolysis reaction was divided into devolatilization and chemical reaction processes to understand the effect of temperature on the evolution of different functional groups.It was found that the O(2)H···O(6)hydrogen bond structure could be destroyed by the salts to lower the initial pyrolysis temperature.NaCl can catalyze the ring opening reactions during cellulose pyrolysis,while MgCl_(2) mainly promotes the intramolecular dehydration reactions.