Catalytic water splitting involves two main half-reactions: the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER). These reactions can occur in acidic, neutral, or alkaline conditions and typically require different types of catalysts to proceed efficiently.
1. Oxygen Evolution Reaction (OER): This reaction occurs at the anode and involves the oxidation of water to produce oxygen gas, protons, and electrons. \[ 2H_2O \rightarrow O_2 + 4H^+ + 4e^- \] 2. Hydrogen Evolution Reaction (HER): This reaction occurs at the cathode and involves the reduction of protons to produce hydrogen gas. \[ 4H^+ + 4e^- \rightarrow 2H_2 \]
