Plasma-catalytic degradation of benzene over Ag-Ce bimetallic oxide catalysts using hybrid surface/packed-bed discharge plasmas
Plasma-catalytic degradation of benzene over Ag-Ce bimetallic oxide catalysts using hybrid surface/packed-bed discharge plasmas
复制标题
使用混合表面/填充床放电等离子体在 Ag-Ce 双金属氧化物催化剂上等离子体催化降解苯
DOI：
10.1016/j.apcatb.2015.11.044
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发表时间：
2016-05-05
影响因子：
22.1
通讯作者：
Wu, Yan
中科院分区：
文献类型：
--
作者：
Jiang, Nan;Hu, Jian;Wu, Yan
采用混合表面/填充床放电（HSPBD）等离子体，在等离子体内催化（IPC）和等离子体后催化（PPC）条件下，对Ag-x Ce 1-x/γ-Al 2 O3催化剂进行了等离子体辅助催化降解苯的研究。为了研究等离子体-催化过程中催化剂位置对放电特性的影响及其协同效应，将催化剂分别引入表面放电区（I区）和填充床放电区（II区）的内部和下游，考察了催化剂在这两个系统中的苯降解性能. Ag/Ce摩尔比和水蒸气的影响也进行了研究，在苯的降解效率和CO2的选择性。等离子体与Ag-x Ce 1-x/γ-Al 2 O3催化剂的联合降解与单纯等离子体降解相比，反应性能明显提高，且联合降解效率是协同效应而非简单的加和效应。此外，排放产物（O-3和NOx）和有害中间产物（甲酸和CO）的排放显着抑制与催化剂的引入。当SIE为400 J/L时，Ag_（0.9）Ce_（0.1）/γ-Al_2 O_3催化剂的苯降解率最高，为96.2%，CO_2选择性最高，为77.3%。这一结果表明，一定比例的Ag和Ce物种在催化剂上的相互作用能够活化表面晶格并产生更多的表面吸附氧（O-ads），这有利于等离子体催化氧化反应。PPC工艺能更有效地分解O-3和破坏苯，特别是当催化剂引入区域II下游时。在等离子体催化体系中加入少量的水蒸气可以提高催化剂的活性，但水蒸气的进一步增加会对催化剂的活性产生明显的负面影响。(C)2015爱思唯尔B. V.保留所有权利。
Plasma-assisted catalysis has been employed for the degradation of benzene by hybrid surface/packed-bed discharge (HSPBD) plasmas over a series of Ag-x Ce1-x/gamma-Al2O3 catalysts in in-plasma catalysis (IPC) and post-plasma catalysis (PPC) configurations. In order to study the influence of catalysts placement on discharge characteristics and the consequent synergetic effect in plasma-catalysis process, the catalysts were introduced inside and downstream the surface discharge region (region I) and packed-bed discharge region (region II), respectively, and the benzene degradation performance was investigated in these systems. The effects of the Ag/Ce molar ratio and water vapor have also been investigated in terms of benzene degradation efficiency and CO2 selectivity. Compared with the plasma-only process, the combination of plasma with Ag-x Ce1-x/gamma-Al2O3 catalyst significantly improved the reaction performance, and the combined degradation efficiency is a synergistic effect rather than simply an additive effect. Besides, the emission of discharge products (O-3 and NOx) and hazardous intermediates (formic acid and CO) was markedly suppressed with the introduction of catalyst. The highest benzene degradation efficiency of 96.2% and CO2 selectivity of 77.3% can be achieved with Ag0.9Ce0.1/gamma-Al2O3 catalyst at the SIE of 400J/L. This result suggests that the interaction between a certain proportion of Ag and Ce species over the catalyst is capable of activating the surface lattice and generating more surface adsorbed oxygen (O-ads), which favors the plasma-catalytic oxidation reaction. PPC processes can decompose O-3 and destroy benzene more effectively than IPC processes, especially when the catalyst was introduced downstream the region II. Adding a small amount of water vapor into plasma-catalysis system enhanced the catalyst activity, however, further increased the water vapor caused an obvious negative impact on the catalyst activity. (C) 2015 Elsevier B.V. All rights reserved.