Hisai Yudai, Murakami Kota, Kamite Yukiko, Ma Quanbao, Vøllestad Einar, Manabe Ryo, Matsuda Taku, Ogo Shuhei, Norby Truls, Sekine Yasushi
Department of Applied Chemistry, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo, 169-8555, Japan.
Chem Commun (Camb). 2020 Mar 4;56(18):2699-2702. doi: 10.1039/c9cc08757e. Epub 2020 Feb 12.
This is the first direct observation that surface proton hopping occurs on SrZrO perovskite even under a H (i.e. dry) atmosphere. Understanding proton conduction mechanisms on ceramic surfaces under a H atmosphere is necessary to investigate the role of proton hopping on the surface of heterogeneous catalysts in an electric field. In this work, surface protonics was investigated using electrochemical impedance spectroscopy (EIS). To extract the surface proton conduction, two pellets of different relative densities were prepared: a porous sample (R.D. = 60%) and a dense sample (R.D. = 90%). Comparison of conductivities with and without H revealed that only the porous sample showed a decrease in the apparent activation energy of conductivity by supplying H. H/D isotope exchange tests revealed that the surface proton is the dominant conductive species over the porous sample with H supply. Such identification of a dominant conductive carrier facilitates consideration of the role of surface protonics in chemical reactions.
这是首次直接观察到即使在H（即干燥）气氛下，质子在SrZrO钙钛矿表面也会发生跳跃。了解H气氛下陶瓷表面的质子传导机制对于研究质子跳跃在电场中多相催化剂表面的作用是必要的。在这项工作中，使用电化学阻抗谱（EIS）研究了表面质子学。为了提取表面质子传导，制备了两种不同相对密度的颗粒：多孔样品（相对密度=60%）和致密样品（相对密度=90%）。有H和无H时电导率的比较表明，只有多孔样品在供应H时显示出电导率表观活化能的降低。H/D同位素交换测试表明，在供应H的情况下，表面质子是多孔样品上的主要导电物种。这种对主要导电载流子的识别有助于考虑表面质子学在化学反应中的作用。
