Efficient Photothermochemical Dry Reforming of Methane over Ni Supported on ZrO2 with CeO2 Incorporation
Efficient Photothermochemical Dry Reforming of Methane over Ni Supported on ZrO2 with CeO2 Incorporation
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DOI：
10.1016/j.cattod.2022.05.014
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发表时间：
2022-05
期刊：
影响因子：
5.3
通讯作者：
Zichen Du;Fuping Pan;Xiaokun Yang;Lingzhe Fang;Yang Gang;Siyuan Fang;Tao Li;Y. Hu;Ying Li
中科院分区：
文献类型：
--
作者：
Zichen Du;Fuping Pan;Xiaokun Yang;Lingzhe Fang;Yang Gang;Siyuan Fang;Tao Li;Y. Hu;Ying Li
太阳能驱动的甲烷光热化学干法重整技术(PTC-DRM)在解决全球气候问题方面受到越来越多的关注，但仍面临稳定性差的挑战，尤其是镍基催化剂。在这里，我们开发了一种策略，通过在CeO2/ZrO2上负载Ni纳米颗粒来提高镍基催化剂的PTC-DRM活性和稳定性。在70 0℃、光照30个太阳的条件下，得到的Ni-CeO_2/ZrO_2催化剂在连续48小时的实验中，H_2和CO的产生率分别为713和693mmolg·−_1h·−_1，远高于无Ce的Ni/ZrO_2催化剂(H_2为542mmolg·−_1h−_1，CO为534mmolg·−_1h·−_1)。在相同温度下的光热化学性能和热化学性能的比较表明，少量CeO2的引入使CH4和CO2的转化活化能从黑暗中的68.6kJ·−1和62.9kJ·moL−1降低到光下的54.7kJ·mo1和57.7kJ·mol1。通过原位漂移和催化剂表征对反应机理进行了研究，结果表明，在光照条件下，Ni的等离子体效应减轻了焦炭沉积，有利于DRM的活性和稳定性。CeO2作为催化剂的助剂，增强了金属-载体之间的相互作用，有利于持续产生氧空位，促进碳酸盐中间体的解离，减缓光照射下的结焦，从而提高了PTC-DRM的活性和稳定性。这项研究对于设计具有成本效益的镍基催化剂和反应系统至关重要，这些催化剂和反应系统用于温室气体转化，以利用可持续的太阳能生产合成气。
Solar-driven photothermochemical dry reforming of methane (PTC-DRM) has attracted increasing attention to address global climate issues yet still faces challenges of poor stability, especially for Ni-based catalysts. Herein, we developed a strategy to improve PTC-DRM activity and stability of Ni-based catalysts by supporting Ni nanoparticles on CeO2incorporated ZrO2. At 700 °C under 30 suns light irradiation, the resulting Ni-CeO2/ZrO2exhibited elevated and stable PTC-DRM with H2and CO production rates of 713 and 693 mmol g−1h−1during a continuous 48 h test, respectively, much higher than those of Ce-free Ni/ZrO2(542 mmol g−1h−1for H2and 534 mmol g−1h−1for CO in a 24 h test). The comparisons between photothermochemical and thermochemical performance at the same temperatures indicate that introducing a small amount of CeO2lowers the activation energies of CH4and CO2conversions from 68.6 and 62.9 kJ mol−1in the dark to 54.7 and 57.7 kJ mol−1under light, respectively. Mechanism investigation was performed through in situ DRIFTS and catalysts characterization before and after the PTC-DRM reaction, revealing that the plasmonic effect from Ni mitigates coke deposition and benefits the DRM activities and stability under light illumination. CeO2, serving as a promoter, enhances metal-support interaction, which also plays beneficial effects in continuously generating oxygen vacancies, facilitating the dissociation of carbonate intermediates, and mitigating coke deposition under light irradiation, thus boosting PTC-DRM activity and stability. This study is essential for designing cost-effective Ni-based catalysts and reaction systems for greenhouse gases conversion to produce syngas using sustainable solar energy.