Trace mono-atomically dispersed rhodium on zeolite-supported cobalt catalyst for the efficient methane oxidation
Trace mono-atomically dispersed rhodium on zeolite-supported cobalt catalyst for the efficient methane oxidation
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DOI：
10.1038/s42004-018-0044-9
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发表时间：
2018-08-01
影响因子：
5.9
通讯作者：
Kobayashi, Hirokazu
中科院分区：
文献类型：
--
作者：
Hou, Yuhui;Nagamatsu, Shinichi;Kobayashi, Hirokazu
甲烷部分氧化是一种很有前途的高效合成气制备方法。为了使用普通不锈钢反应器实施该方法，需要在650 ℃或更低温度下起作用的廉价催化剂。然而，贱金属催化剂通常需要高得多的温度，并且它们通过再氧化和焦炭形成而失活。在这里，我们报告了用痕量的单原子分散的铑（0.005wt%）对沸石负载的3wt%钴催化剂进行改性显著地改善了催化性能和耐久性。钴/丝光沸石由于钴的氧化而几乎没有活性，但用铑改性的催化剂在650 ℃下连续地提供85-86%的甲烷转化率和90-91%的CO选择性，H2/CO比为2.0，而没有严重的结焦。在反应期间，单原子分散的铑经由氢溢出将钴氧化物转化为Co-0活性物质。沸石载体的使用是高催化性能的关键。
The partial oxidation of methane is a promising method for the efficient production of syngas. To implement this process using common stainless steel reactors, an inexpensive catalyst that functions at 650 degrees C or below is necessary. However, base metal catalysts typically require much higher temperatures, and they are deactivated by re-oxidation and coke formation. Here we report that modification of a zeolite-supported 3 wt% cobalt catalyst with a trace amount of mono-atomically dispersed rhodium (0.005 wt%) dramatically improves catalytic performance and durability. Cobalt/mordenite is nearly inactive due to the oxidation of cobalt, but the catalyst modified with rhodium continuously gives 85-86% methane conversion and 90-91% CO selectivity with an H-2/CO ratio of 2.0 without serious coking at 650 degrees C. During the reaction, mono-atomically dispersed rhodium converts cobalt oxide to Co-0 active species via hydrogen spillover. Use of the zeolite support is key to the high catalytic performance.