Nagakawa Kaho, Sampei Hiroshi, Takahashi Ayako, Sasaki Jun, Higo Takuma, Mori Naoya, Sato Hideto, Sekine Yasushi
Department of Applied Chemistry, Waseda University 3-4-1, Okubo, Shinjuku Tokyo 169-8555 Japan
Murata Manufacturing Co. Ltd 1-10-1, Higashikotari, Nagaokakyo-shi Kyoto 617-8555 Japan.
RSC Adv. 2022 Sep 7;12(39):25565-25569. doi: 10.1039/d2ra04974k. eCollection 2022 Sep 5.
The effect of OH-groups on the surface of a Ni catalyst for low-temperature (473 K) steam reforming of methane in an electric field (EF) was investigated. Ni-doped YSZ (ZrYNiO) was chosen as a highly active catalyst for this purpose. The effects on catalyst activity of adding hydrogen and steam in the pre-treatment were assessed with and without EF. When an EF was applied, activity increased irrespective of the electronic state of Ni, whereas the metallic Ni state was necessary for activity without EF. Furthermore, the highest activity with EF was observed for the pre-treatment with a mixture of H and HO. Investigation of the superiority using XPS measurements showed an increase in the amount of Ni(OH), OH groups and HO near the surface after the activity test, which are regarded as the reaction sites with EF. This finding suggests that a pre-treatment with steam increases the surface OH groups and Ni(OH) on the Ni catalyst, and enhances surface proton conduction, thereby improving the activity.
研究了羟基对用于低温（473K）甲烷蒸汽重整的镍催化剂在电场（EF）中的影响。为此选择了镍掺杂的氧化钇稳定氧化锆（ZrYNiO）作为高活性催化剂。在有和没有电场的情况下，评估了预处理中添加氢气和蒸汽对催化剂活性的影响。当施加电场时，无论镍的电子状态如何，活性都会增加，而没有电场时，金属镍状态是活性所必需的。此外，用氢气和水的混合物进行预处理时，在电场作用下观察到最高活性。使用X射线光电子能谱（XPS）测量对这种优势进行的研究表明，活性测试后表面附近的氢氧化镍、羟基和水的量增加，这些被认为是与电场的反应位点。这一发现表明，蒸汽预处理增加了镍催化剂表面的羟基和氢氧化镍，并增强了表面质子传导，从而提高了活性。
