Nikkelifosfori

Nikkelifosfori is a family of nickel–phosphide compounds formed from nickel and phosphorus. The most studied phase is nickel phosphide Ni2P, but the system also includes other stoichiometries such as Ni5P4 and Ni12P5. These materials are noted for their catalytic properties and relative stability under catalytic conditions.

Ni2P and related phosphides are metallic, with high electrical conductivity. They occur as intermetallic solids and as nanoscale particles. The exact crystal structure varies by phase, but all share a nickel-to-phosphorus composition that influences catalytic activity. They tend to be relatively hard and thermally robust, though surface oxidation to nickel oxides or phosphides can occur upon air exposure.

Synthesis methods include phosphidation of nickel precursors (such as nickel oxides or nickel salts) using phosphorus sources like PH3, red phosphorus, or organophosphorus compounds at elevated temperatures. Other routes comprise solvothermal or hydrothermal methods, electrochemical deposition followed by phosphidation, and chemical vapor deposition.

Applications of nickel phosphides center on catalysis. Ni2P and related phosphides serve as active catalysts for hydrodesulfurization and related upgrading reactions, and are widely studied as non-noble-metal catalysts for the hydrogen evolution reaction and for CO2 reduction. They are also used as supports or promoters in various heterogeneous catalytic systems.

Safety: Nickel compounds can cause allergic reactions and other health effects; phosphorus-containing materials can be toxic, and phosphine is highly toxic and flammable. Handle nickel phosphides with appropriate personal protective equipment, good ventilation, and careful control of atmosphere during synthesis and handling.

See also: nickel phosphide; catalysis; hydrogen evolution reaction; nickel; phosphorus.