介质填充材料对低温等离子体分解CO_(2)的研究

低温等离子体内部存在很多高活性粒子可以促进CO_(2)气体在常温下分解。为了提高CO_(2)的分解效率,探索CO_(2)减排的新途径。研究了介质材料(γ-Al_(2)O_(3)、石英棉、CaO)加入时,等离子体与CO_(2)的反应情况及不同填充材料对该反应的影响。研究表明,加入介质填充材料会显著提高CO_(2)的分解效率,且加入石英棉时对CO_(2)的分解效率最高;填充材料粒径在250μm时,CO_(2)转化率最高。

进气流量对滑动电弧放电分解CO_(2)的瞬态电-光-热特性和转化性能的影响

进气流量作为影响滑动电弧放电特性的关键操作参数,直接关系到滑动电弧分解CO_(2)的转化性能。该文拟通过实验研究进气流量对滑动电弧放电分解CO_(2)的电-光-热特性及其对转化性能的影响。为此搭建了滑动电弧放电的瞬态电-光-热特性同步原位诊断平台,其中,热特性通过高速纹影技术表征。借助搭建的诊断平台,开展了不同进气流量(1.5~10 L/min)下滑动电弧放电分解CO_(2)的实验,并对比分析进气流量对滑动电弧运动特征(即放电周期和电弧短路事件)、等离子体发光区和高温气流区面积、注入能量和CO_(2)转化性能参数的影响规律。实验结果表明:滑动电弧的放电周期随着进气流量的增大而减小,且变化趋势近似服从指数衰减;等离子体发光区和高温气流区的面积均与进气流量呈正相关,表明进气流量的增大有利于扩大活性粒子分布区域并强化对流换热过程,从而提升CO_(2)的转化性能;过高的进气流量(10L/min)会引发两类电弧短路事件,而短路事件的频繁发生会抑制滑动电弧的作用区域和对流换热过程,导致CO_(2)转化性能劣化。最后,提出了进气流量对滑动电弧放电分解CO_(2)的影响机制,将有助于理解反应器内气流与等离子体之间的相互作用关系,为反应器操作参数的调控提供指导。

Rational design and precise manipulation of nano‐catalysts

Nano‐catalysis plays a vital role in the chemical transformations and significantly impacts the booming modern chemical industry.The rapid technological enhancements have resulted in serious energy and environmental issues,which are currently spurring the exploration of the novel nano‐catalysts in diverse fields.In order to develop the efficient nano‐catalysts,it is essential to understand their fundamental physicochemical properties,including the coordination structures of the active centers and substrate‐adsorbate interactions.Subsequently,the nano‐catalyst design with precise manipulation at the atomic level can be attained.In this account,we have summarized our extensive investigation of the factors impacting nano‐catalysis,along with the synthetic strategies developed to prepare the nano‐catalysts for applications in electrocatalysis,photocatalysis and thermocatalysis.Finally,a brief conclusion and future research directions on nano‐catalysis have also been presented.