Research

Physical Sciences

Title :

Investigation of Competing Oxygen and Chlorine Evolution Reactions in Metal Phosphides for Sea Water Electrolysis: An Ab-initio Study

Area of research :

Physical Sciences

Principal Investigator :

Dr. Alpa Dashora, Maharaja Sayajirao University Of Baroda, Gujarat

Timeline Start Year :

2023

Timeline End Year :

2026

Contact info :

Equipments :

Details

Executive Summary :

The majority of energy sources used globally are carbon-based, accounting for 85% of all energy resources. However, due to rapid use and environmental impact, alternative energy sources are needed, such as hydrogen, which has high gravimetric energy density and minimal environmental impacts. Electrocatalysis is one way to produce hydrogen and oxygen from water splitting, but the rapid reduction in fresh water resources requires advancements in electrocatalysts that can use sea water directly in electrolysers. The presence of chloride ions in sea water, such as NaCl, leads to competitive electrochemical reactions against HER/OER. At low pH conditions, chlorine evolution reaction (ClER) competes with OER by producing Cl2, while higher pH conditions lead to competition between hypochlorite species formation or oxygen. Chloride ions also affect the HER activity at the cathodic site, obstructing active HER centers. Various materials, such as metal hydroxides, nitrides, borides, phosphides, selenides, and hybrid catalysts, have been actively studied. This proposed work aims to study competing ClER with OER at anodic sites considering alkaline to near neutral pH conditions using density functional theory (DFT). The study will mainly focus on transition metal phosphides MxPy and bimetal phosphides M_x M_z^' P_y. The study aims to facilitate selective OER activity near neutral pH conditions to prohibit hypochlorite species formation. Screened materials will be used to understand the effect on OER activity lead by various ions presented in sea water.

Total Budget (INR):

25,53,870

Organizations involved