基于微量热法对多孔碳与双氧水相互作用过程的传质阻力分析  

Mass transfer resistance analysis of the interaction between porous carbon and hydrogen peroxide based on microcalorimetry

作　　者：曹健 叶南南 蒋管聪 覃瑶 王士博 朱家华 陆小华[1] CAO Jian;YE Nannan;JIANG Guancong;QIN Yao;WANG Shibo;ZHU Jiahua;LU Xiaohua(State Key Laboratory of Materials-Oriented Chemical Engineering,Nanjing Tech University,Nanjing 211816,Jiangsu,China)

机构地区：[1]南京工业大学材料化学工程国家重点实验室,江苏南京211816

出　　处：《化工学报》2022年第6期2543-2551,共9页CIESC Journal

基　　金：国家自然科学基金项目(91934302,21838004,21921006,21490580,21978128)。

摘　　要：多孔材料作为催化剂对现代化学工业起到重要推动作用,但其纳米受限孔道造成的界面传递问题不容忽视。直接法合成双氧水(H_(2)O_(2))过程中,揭示H_(2)O_(2)脱附过程传递与反应竞争博弈的介尺度机制是提高产率的关键。线性非平衡热力学为解耦界面扩散及反应提供了统一框架,但缺少合适通量测定方法。因此,本文设计多孔碳与H_(2)O_(2)相互作用的微量热实验,结合分子模拟及孔结构表征实验揭示多孔碳材料的界面传递结构,实现了非平衡热力学的定量传质阻力分析,进一步获取了表界面浓度场的动态变化。研究结果表明:微量热法是定量解耦并揭示扩散-反应机制的有效线性非平衡热力学阻力分析方法;介孔结构、生物骨架结构及担载1%(质量)Pd元素均能增强H_(2)O_(2)在多孔碳中的传质通量,但实现超高通量需要扩散与反应阻力的匹配;非平衡热力学阻力解耦方法是揭示多相反应过程介尺度机制的重要定量描述方法,有望为过程的调控及优化提供理论依据。Porous materials play an important role in modern chemical industry,but the interfacial transfer phenomena caused by their nano-confinement pores cannot be ignored.For direct oxidation synthesizing hydrogen peroxide(H_(2)O_(2)),revealing the mesoscale relationship between mass transfer of desorbing H_(2)O_(2) and reaction is the key to improving the yield.Linearized non-equilibrium thermodynamics has provided a unified framework for decoupling the interfacial diffusion and reaction,but in this case,a suitable method of measuring mass transfer flux was lacked.Therefore,the microcalorimetry experiments measuring the heat effect of interaction between porous carbons and H_(2)O_(2) were designed in this paper.With the help of molecular simulation and pore characterization,the structures for interfacial transfer were revealed,and the quantitative mass transfer resistance analysis of non equilibrium thermodynamics was realized,then the dynamic change of H_(2)O_(2) concentration was obtained.The results showed that microcalorimetry is an effective linearized non-equilibrium thermodynamic resistance analysis method.Mesoporous structure, biological skeleton texture and supporting 1%(mass) palladium can enhance the mass transfer flux of H_(2)O_(2) in porous carbon, but the realization of ultra-high flux requires the matching of diffusion and reaction resistance. The resistance decoupling of non-equilibrium thermodynamics is an important quantitative description method to reveal the mesoscale mechanism of heterogeneous reaction process, which is expected to provide a theoretical basis for the regulation and optimization of the process.

关 键 词：多孔材料 界面传递 介尺度 非平衡热力学 扩散 反应 微量热 传质阻力 

分 类 号：O414.19[理学—理论物理]