Elucidation of the mechanism for hydrogen permeation of Pd-free vanadium membrane and application for hydrogen separation from anmonia

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K04760
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 26040:Structural materials and functional materials-related
• Research Institution: Suzuka National College of Technology
• Principal Investigator: Tomonori Nambu 鈴鹿工業高等専門学校, その他部局等, 教授 (10270274)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 水素分離 / バナジウム酸化物 / 金属膜 / 酸化 / 還元

Outline of Final Research Achievements

The effects of surface V species on the hydrogen permeability through V membrane without Pd-catalyst overlayer are investigated by the hydrogen permeation test and the XPS measurement. The steady-state hydrogen permeation flux through Pd-coating free V membrane after the redox treatment is more than twice that of the non-treated membrane. The fraction of V0+/V2p3/2 on the surface of membrane just after the redox treatment is approximately 2%, and the amount of V3+ is larger than V4+. This fine balance of the V species composition on the surface is found to induce the high hydrogen permeability. The composition of V species on the surface of the redox-treated membrane changes to V3+ < V4+ by oxidation of V3+ to V4+ during the hydrogen permeation test for a long time. The loss of the fine balance in the composition of V species is considered to be the cause of the degradation of hydrogen permeability.

Free Research Field

金属材料

Academic Significance and Societal Importance of the Research Achievements

水素を２次エネルギー源とした水素社会の構築に向けて、高純度の水素燃料を効率良く低コストに製造する技術の確立が求められている。こうした背景の中、金属膜による水素分離・精製法は最も効率良く超高純度の水素が得られる方法として注目されている。本研究では、高価な貴金属を使用しないバナジウム単体膜での水素透過反応機構を明らかにした。また、これまで水素透過反応を阻害していると考えられてきたバナジウム酸化物層が水素透過反応に効果的に寄与しているという新たな学術的知見を明らかにした。この研究成果により、将来の水素需要拡大に備えた完全貴金属フリーバナジウム膜の開発が加速する。