Recent Development of Nickel-Based Electrocatalysts for Urea Electrolysis in Alkaline Solution

Area of Science:

• Electrochemistry
• Materials Science
• Sustainable Energy

Background:

• Urea electrolysis presents a sustainable hydrogen production method with a lower theoretical cell potential (0.37 V) compared to water electrolysis (1.23 V).
• This process also aids in rectifying urea-rich wastewater pollution, contributing to environmental remediation.
• Nickel-based materials are extensively studied as cost-effective electrocatalysts for urea electrolysis.

Purpose of the Study:

• To review the fundamentals of urea electrolysis, including the urea oxidation reaction (UOR) and hydrogen evolution reaction (HER).
• To discuss strategies for designing effective monofunctional and bifunctional electrocatalysts for UOR and HER.
• To summarize the performance, mechanisms, and influencing factors of nickel-based electrocatalysts in urea electrolysis.

Main Methods:

• Review of existing literature on nickel-based electrocatalysts for urea electrolysis.
• Analysis of catalytic performance, reaction mechanisms, and influencing factors (morphology, composition, kinetics).
• Discussion of strategies for designing electrocatalysts for UOR, HER, and bifunctional applications.

Main Results:

• Nickel-based materials (alloys, oxides, chalcogenides, nitrides, phosphides) are effective electrocatalysts for urea electrolysis.
• Factors like morphology, composition, and electrode/electrolyte kinetics significantly impact catalyst activity.
• Both monofunctional (UOR or HER) and bifunctional (UOR and HER) nickel-based catalysts have been explored.

Conclusions:

• Nickel-based electrocatalysts are crucial for advancing urea electrolysis and achieving a low-carbon future.
• Further research is needed to address challenges and optimize bifunctional electrocatalysts for urea-based energy conversion.
• Future prospects include urea fuel cells and photoelectrochemical urea splitting technologies.