A highly active and stable Co4N/γ-Al2O3 catalyst for CO and CO2 methanation to produce synthetic natural gas (SNG)
A highly active and stable Co4N/γ-Al2O3 catalyst for CO and CO2 methanation to produce synthetic natural gas (SNG)
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DOI：
10.1016/j.cej.2014.10.073
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发表时间：
2015-02
影响因子：
15.1
通讯作者：
Rauf Razzaq;Chunshan Li;M. Usman;Kenzi Suzuki;Suojiang Zhang
中科院分区：
文献类型：
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作者：
Rauf Razzaq;Chunshan Li;M. Usman;Kenzi Suzuki;Suojiang Zhang
采用NH3和H2程序升温反应法制备了不同金属负载量的Co 4 N/γ-Al 2 O3和Co/γ-Al 2 O3催化剂，用于CO和CO2的共甲烷化反应。采用N2吸附-脱附、XRD、XPS、TEM-SAED、H2、CO、CO2-TPD等技术对催化剂进行了表征。结果表明，Co 4 N催化剂比Co金属负载催化剂具有更高的活性，这是由于其增强的吸附能力、均匀的金属分散以及上级金属与载体的相互作用。在所研究的催化剂中，金属负载量为20wt%的20 Co 4 N/γ-Al 2 O3催化剂表现出最好的性能。该催化剂在200 ~ 300 °C具有较高的甲烷生成活性，并保持了较高的产物选择性（> 98%）。还在350 °C和增加的气时空速（GHSV; 10，000 h-1）下进行了20 Co 4 N/γ-Al 2 O3的250 h稳定性测试。使用XRD、TEM和TGA分析进一步表征废催化剂。结果表明，该催化剂具有很高的抗金属烧结和抗积碳能力，即使在较高的GHSV下，也能保持较高的CO和CO2转化率和CH 4选择性。
Co4N/γ-Al2O3and Co/γ-Al2O3catalysts with different metal loadings were prepared by NH3and H2-temperature programmed reaction method for the co-methanation of carbon oxides (CO and CO2). The catalysts were characterized by N2adsorption–desorption, XRD, XPS, TEM-SAED, H2, CO, and CO2-TPD techniques. Results showed that the Co4N catalysts had higher activity than Co metal-supported catalysts due to their enhanced adsorption capacity, uniform metal dispersion, and superior metal-support interaction. Among the catalysts studied, 20Co4N/γ-Al2O3catalyst with 20 wt% metal loading showed the best performance. This catalyst achieved higher activity for CH4formation between 200 and 300 °C and maintained high product selectivity (⩾98%). A 250 h stability test for 20Co4N/γ-Al2O3was also conducted at 350 °C and increased gas hourly space velocity (GHSV; 10,000 h−1). The spent catalyst was further characterized using XRD, TEM, and TGA analysis. Results revealed that the catalyst was highly resistant to metal sintering and carbon deposition, whereas high CO and CO2conversion and CH4selectivity were maintained even at a higher GHSV.