報告書番号

W03013

タイトル（和文）

硫黄サイクルハイブリッド水素製造に適したアノード電極材料の探索 -―耐食性と導電性を両立するパイロクロア型酸化物の検討―-

タイトル（英文）

Survey of Anode Material used for Sulfur-based Hybrid Hydrogen Production Electrolytic Cell‐ Study of Pyrochlore with High Corrosion Resistance and Electrical Conductivity ‐

概要 （図表や脚注は「報告書全文」に掲載しております）

水素エネルギー社会の到来が予想される昨今、低コストかつプロセスが簡易な硫黄サイクルハイブリッド法が水素製造法として注目されている。本報では、本製造法の高効率化に必要な技術課題を明確にするとともに、電解用アノード極の探索、電極材の導電性の発現手法を検討した。(1) 先行研究を分析した結果、水素製造効率の向上には、耐食性に優れ過電圧が小さい高性能触媒電極の開発による電解電力量の低減、および高珪素鋳鉄等脆性材料の実用化による硫酸の濃縮・分解エネルギー量の低減が必要であることが判った。(2) アノード極の探索を行った結果、電解環境中での耐食性の点からチタン酸化物セラミックスが有望であった。また、セラミックス組成の不定比化の新技法を採用することにより、耐食性を維持しつつ電気分解環境中で導電性を発現することができ、アノード極の作製指針を得た。

概要 （英文）

According to the establishment of hydrogen energy cycle in the near future, sulfur-based hybrid cycle for hydrogen production is attracted the attention as a low cost and a simple hydrogen producing process through the electrolysis of 2H2O+SO2 H2 + H2SO4 at approximately 353K and through the thermal decomposition of H2SO4 H2O +SO2 +1/2O2 at approximately 1123K. In order to establish the hybrid hydrogen production process, it is necessary to clarify the technical issues for high efficient hydrogen producing and to develop an anode material substitute for platinum group.In this paper, the technical issues were clarified. Also, candidate anode materials were surveyed, and some techniques of electric conductivity appearance for the anode material were proposed.(1) From the survey of a lot of published papers, it was clarified that the development of high quality anode which has high corrosion resistance and low electrolysis potential was useful for high efficient hydrogen producing and applying a high silicon-iron material to the structure material of hydrogen production system was useful for reducing the concentration and decomposition of sulfuric acid.(2) From the survey of candidate anode materials substitute for platinum group, RE2-xTi2O7- pyrochlores (RE=Yb, Y, Gd, Sm, Nd, Pr, La) were available for anode material of the electrolysis cell. In addition, some new techniques were proposed, such as A-site non-stoichiometry techniques. Because the corrosion resistances of the improved pyrochlores were maintained under the electrolysis condition , an anode material design guide might be obtained.

報告者

キーワード