Synthesis and Electrocatalytic Activity of Ammonium Nickel Phosphate, [NH4]NiPO4·6H2O, and β-Nickel Pyrophosphate, β-Ni2P2O7: Catalysts for Electrocatalytic Decomposition of Urea

Andrew G Meguerdichian; Tahereh Jafari; Md R Shakil; Ran Miao; Laura A Achola; John Macharia; Alireza Shirazi-Amin; Steven L Suib

doi:10.1021/acs.inorgchem.7b02658

Synthesis and Electrocatalytic Activity of Ammonium Nickel Phosphate, [NH₄]NiPO₄·6H₂O, and β-Nickel Pyrophosphate, β-Ni₂P₂O₇: Catalysts for Electrocatalytic Decomposition of Urea

Inorg Chem. 2018 Feb 19;57(4):1815-1823. doi: 10.1021/acs.inorgchem.7b02658. Epub 2018 Feb 7.

Authors

Andrew G Meguerdichian¹, Tahereh Jafari¹, Md R Shakil², Ran Miao², Laura A Achola², John Macharia², Alireza Shirazi-Amin², Steven L Suib^{1

2

3}

Affiliations

¹ Institute of Materials Science, University of Connecticut , U-3136, 97 N. Eagleville Road, Storrs, Connecticut 06269, United States.
² Department of Chemistry, University of Connecticut , U-3060, 55 N. Eagleville Road, Storrs, Connecticut 06269, United States.
³ Department of Chemical & Biomolecular Engineering, University of Connecticut , U-3222, 191 Auditorium Road, Storrs, Connecticut 06269, United States.

PMID: 29412657
DOI: 10.1021/acs.inorgchem.7b02658

Abstract

Electrocatalytic decomposition of urea for the production of hydrogen, H_2, for clean energy applications, such as in fuel cells, has several potential advantages such as reducing carbon emissions in the energy sector and environmental applications to remove urea from animal and human waste facilities. The study and development of new catalyst materials containing nickel metal, the active site for urea decomposition, is a critical aspect of research in inorganic and materials chemistry. We report the synthesis and application of [NH₄]NiPO₄·6H₂O and β-Ni₂P₂O₇ using in situ prepared [NH₄]₂HPO₄. The [NH₄]NiPO₄·6H₂O is calcined at varying temperatures and tested for electrocatalytic decomposition of urea. Our results indicate that [NH₄]NiPO₄·6H₂O calcined at 300 °C with an amorphous crystal structure and, for the first time applied for urea electrocatalytic decomposition, had the greatest reported electroactive surface area (ESA) of 142 cm²/mg and an onset potential of 0.33 V (SCE) and was stable over a 24-h test period.