NOx storage and reduction assisted by non-thermal plasma over Co/Pt/Ba/γ-Al2O3 catalyst using CH_(4) as reductant

NOx storage and reduction(NSR)technology has been regarded as one of the most promising strategies for the removal of nitric oxides(NOx)from lean-burn engines,and the potential of the plasma catalysis method for NOx reduction has been confirmed in the past few decades.This work reports the NSR of nitric oxide(NO)by combining non-thermal plasma(NTP)and Co/Pt/Ba/γ-Al2O3(Co/PBA)catalyst using methane as a reductant.The experimental results reveal that the NOx conversion of NSR assisted by NTP is notably enhanced compared to the catalytic efficiency obtained from NSR in the range of 150°C–350°C,and NOx conversion of the 8%Co/PBA catalyst reaches 96.8%at 350°C.Oxygen(O_(2))has a significant effect on the removal of NOx,and the NOx conversion increases firstly and then decreases when the O_(2)concentration ranges from 2%to 10%.Water vapor reduces the NOx storage capacity of Co/PBA catalysts on account of the competition for adsorption sites on the surface of Co/PBA catalysts.There is a negative correlation between sulfur dioxide(SO_(2))and NOx conversion in the NTP system,and the 8%Co/PBA catalyst exhibits higher NOx conversion compared to other catalysts,which shows that Co has a certain SO_(2)resistance.

MOF衍生Co_(3)O_(4)/ZrO_(2)介孔八面体:优化电荷转移和中间体转化用于高效CO_(2)光还原

调控电荷转移和反应路径是促进光催化CO_(2)还原的两种有效策略.本研究通过热解UIO-66@ZIF-67核壳八面体,合成了Co_(3)O_(4)/ZrO_(2)介孔八面体.该介孔八面体由高度分散的小尺寸纳米颗粒组装而成,平均颗粒尺寸为13 nm,平均孔径为5.8 nm,比表面积为43.11 m^(2)g^(-1).受益于活性位点设计,电荷转移动力学和CO_(2)吸附得以增强.此外,密度泛函理论计算结果显示,ZrO_(2)能够有效调控CO_(2)还原的反应路径,包括促进CO_(2)活化为*CO_(2)、中间体(*COOH和*CO)的形成、以及减小限速步(*CO→CO)的能垒.因此,Co_(3)O_(4)/ZrO_(2)介孔八面体的周转率高达28.82,是纯Co_(3)O_(4)的16.95倍.

浓度梯度微流控芯片在药物筛选中的应用

微流控芯片技术作为21世纪极具代表性的微型分析平台技术之一,以其试剂消耗低、分析微型化、可集成化、易于控制、自动化和良好的生物相容性等优点而成为研究热点,在生物、医学、食品和环境等多个领域都有杰出表现,尤其是药物筛选领域。其中备受关注的浓度梯度微流控芯片更是取得了显著成果。本文综述了近年来用于药物筛选的浓度梯度纸基芯片、浓度梯度水凝胶芯片、浓度梯度液滴芯片、浓度梯度聚二甲基硅氧烷(PDMS)芯片的研究进展;同时对浓度梯度微流控芯片在单细胞分析、组合药物筛选、三维(3D)细胞培养和细胞微环境模拟等方面的应用及优缺点进行了阐述,并在此基础上对其发展前景进行了展望。