Dry reforming of methane on Ni-Fe-MgO catalysts: Influence of Fe on carbon-resistant property and kinetics
Dry reforming of methane on Ni-Fe-MgO catalysts: Influence of Fe on carbon-resistant property and kinetics
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Ni-Fe-MgO 催化剂上甲烷干重整：Fe 对耐碳性能和动力学的影响
DOI：
10.1016/j.apcatb.2019.118497
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发表时间：
2020-05
期刊：
影响因子：
--
通讯作者：
Zhou Xinggui
中科院分区：
文献类型：
--
作者：
Zhang Tingting;Liu Zhongxian;Zhu Yi-An;Liu Zhicheng;Sui Zhijun;Zhu Kake;Zhou Xinggui
甲烷干法重整(DRM)将两种主要的温室气体转化为合成气体，这是一种用途广泛的化学原料，需要识别出坚固的催化剂。在这一贡献中，我们探索了Fe在氧化镁负载的Ni-Fe合金催化剂中对DRM的促进作用。为此，以溶剂热合成法合成的单一FeNiyMg1-x-y(OH)2(x=0.00-0.07，y=0.00-0.07)为原料，制备了一系列Fe/(Ni+Fe)比(0~0.17)和金属分布均匀的催化剂。760℃和800℃下的催化评价表明，Fe钝化了Ni表面的活性，同时提高了催化剂的耐焦性。用X射线衍射仪、扫描电子显微镜、透射电子显微镜、HAADF-HRTEM、H2-TPR、CO_2(O_2)-TGA和CO_2-TPO等技术对催化剂的结构演变和积炭进行了表征，结果表明，Fe和Ni的合金化提高了催化剂的稳定性。与未处理的镍催化剂相比，废镍铁合金催化剂的结焦量减少，表面碳的类型也由难熔变为易被CO2气化的软碳。Fe还通过平衡Ni表面的亲碳性，提高了合金颗粒表面的亲氧性。FexNi0.07-xMg0.93O-R(x=0.003-0.006)催化剂具有最佳的催化性能。动力学研究和焦炭气化动力学研究表明，Fe减缓了焦炭沉积速度，同时加快了表面焦炭气化速度，但没有改变原生镍催化剂的基本反应机理和动力学特征。Fe的促进作用与接触气氛中的CO_2含量以及合金中的Fe/Ni比密切相关。Ni-Fe合金催化剂在DRM中的稳定性可以归因于整体尺寸减小和表面亲氧性变化的综合作用。铁在提高DRM抗焦性方面所起的作用对重整催化剂和工艺设计都有潜在的帮助。
Dry reforming of methane (DRM) converts two major greenhouse gases into syngas, a versatile chemical feedstock, requiring the identification of a robust catalyst. In this contribution, we explored the promoting effect of Fe in MgO supported Ni-Fe alloy catalysts in DRM. Towards this end, a series of catalysts with varied Fe/(Ni+Fe) ratios (0 to 0.17) and homogeneous metal distribution were prepared from a single FexNiyMg1-x-y(OH)2(x = 0.00–0.07, y = 0.00–0.07) precursor derived from solvothermal synthesis. Catalytic evaluations at 760 °C and 800 °C showed that Fe passivated the activity of Ni surface while promoting the coke-tolerant property. Structural evolution and coke deposition of catalysts were extensively characterized by using XRD, SEM, TEM, HAADF-HRTEM, H2-TPR, CO2(O2)-TGA and CO2-TPO techniques, manifesting that alloying of Fe with Ni had enhanced catalyst stability. Lowered amount of coke was found on spent Ni-Fe alloy catalysts with respect to pristine Ni catalyst, and Fe also changed the type of surface carbon from a refractory type to a soft one that can be readily gasified by CO2. Fe also increased the surface oxyphilicity of alloy particle surface via balancing the otherwise carbon affinity of Ni surface. Optimized catalytic performance was attained by FexNi0.07-xMg0.93O-R (x = 0.003–0.006) catalyst. Kinetic studies and coke gasification kinetic disclosed that Fe slowed down coke deposition rate and concomitantly accelerated surface coke gasification rate, without changing the essential reaction mechanism or kinetic features of pristine Ni catalyst. The promoting effect of Fe was found to be highly dependent on CO2contents in the contacting atmosphere, as well as Fe/Ni ratios in the alloy. The stability of Ni-Fe alloy catalyst in DRM can be ascribed to combined effects from both ensemble size reduction and surface oxyphilicity change. The role Fe plays in enhancing DRM coke-resistant property is potentially useful for alike reforming catalyst and process design.
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影响因子：
22.1
作者：
Mingjue Yu;Kake Zhu;Zhicheng Liu;Haipeng Xiao;Wei Deng;Xinggui Zhou
通讯作者：
Mingjue Yu;Kake Zhu;Zhicheng Liu;Haipeng Xiao;Wei Deng;Xinggui Zhou
DOI：
10.1016/s0167-2991(99)80553-9
发表时间：
1999
期刊：
Studies in Surface Science and Catalysis
影响因子：
--
作者：
M. Fadoni;L. Lucarelli
通讯作者：
M. Fadoni;L. Lucarelli
影响因子：
3.7
作者：
Ruban, AV;Skriver, HL;Norskov, JK
通讯作者：
Norskov, JK
影响因子：
41.2
作者：
R. T. Vang;K. Honkala;S. Dahl;E. K. Vestergaard;J. Schnadt;E. Lægsgaard;B. Clausen;J. Nørskov
通讯作者：
R. T. Vang;K. Honkala;S. Dahl;E. K. Vestergaard;J. Schnadt;E. Lægsgaard;B. Clausen;J. Nørskov
影响因子：
3.3
作者：
Carley, AF;Jackson, SD;Roberts, MW
通讯作者：
Roberts, MW