Thermodynamics: E = 1.24 - 0.059*pH

Dear Chinnasamy,

I'm going to guess that those reported articles concern OER catalysts based on 3d transition metals (Co, Ni/Fe, Mn) or other non-noble materials such as functionalized carbon. These catalysts are generally only stable and OER active in basic solutions. The 1 M concentration is probably to increase conductivity of the working solution, to minimize ohmic drop-related issues.

Dear Jan Vos and Yurii,

Thank you very much for your kind explanation. As you (Jan Vos) suggested most of the articles dealt with non-precious 3D trasition metal based catalysts.

Thanks again for your time and concise answer.