Methanation of carbon dioxide on metal-promoted mesostructured silica nanoparticles
Methanation of carbon dioxide on metal-promoted mesostructured silica nanoparticles
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DOI：
10.1016/j.apcata.2014.08.022
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发表时间：
2014-09-22
影响因子：
5.5
通讯作者：
Sidika, S. M.
中科院分区：
文献类型：
--
作者：
Aziz, M. A. A.;Jalil, A. A.;Sidika, S. M.
研究了金属促进的介孔二氧化硅纳米粒子（MSN）在常压下的CO2甲烷化反应。在623 K及以上温度下，Rh/MSN、Ru/MSN、Ni/MSN、Ir/MSN、Fe/MSN和Cu/MSN催化剂的活性较高。然而，在面积的基础上，Ni/MSN是最活跃的催化剂，而Ir/MSN是最差的催化剂。还研究了催化剂，通过原位FTIR光谱研究阐明每种金属、MSN和金属/MSN在CO2甲烷化中的作用。首先，CO2和H2-在金属位上吸附和解离，形成CO、O和H原子，然后迁移到MSN表面。解离后的CO与MSN氧化物表面相互作用形成桥连羰基和直链羰基，而H原子的存在促进了双齿甲酸根的形成。这三种物质可能是甲烷形成的原因。然而，二齿甲酸盐物种可能是形成甲烷的主要途径。MSN的支持在这一机制中发挥了重要作用。MSN的支持服务的网站羰基物种作为甲烷形成的前体。这些结果为催化，特别是CO2的回收提供了新的前景。(C)2014爱思唯尔有限公司版权所有。
Metal-promoted mesostructured silica nanoparticles (MSN) have been studied for CO2 methanation under atmospheric pressure. In term of activities, high activity was observed on Rh/MSN, Ru/MSN, Ni/MSN, Ir/MSN, Fe/MSN and Cu/MSN at and above 623 K. However, on an areal basis, Ni/MSN was the most active catalyst, while Ir/MSN was the poorest catalyst. The catalysts have also been studied for elucidation of the role of each metal, MSN and metal/MSN in CO2 methanation by in situ FTIR spectroscopy studies. Firstly, CO2 and H-2 was adsorbed and dissociated on metal sites to form CO, O and H atoms, followed by migration onto the MSN surface. The dissociated CO then interacted with oxide surfaces of MSN to form bridged carbonyl and linear carbonyl, while the presence of H atom facilitated the formation of bidentate formate. These three species could be responsible for the formation of methane. However, the bidentate formate species could be the main route to formation of methane. MSN support has been found to play an important role in the mechanism. MSN support served the sites for carbonyl species which act as precursors to methane formation. These results provided new perspectives in the catalysis, particularly in the recycling of CO2. (C) 2014 Elsevier B.V. All rights reserved.