cobaltcarbon

Cobaltcarbon, commonly referred to as cobalt carbide, designates binary cobalt–carbon compounds that form when cobalt is exposed to carbon-rich environments. In the literature it most often denotes two carbide phases: Co2C and Co3C. The stability and exact structure of these phases depend on temperature, pressure, and the surrounding gas composition, and reports sometimes describe them as metastable relative to metallic cobalt and carbon.

Synthesis and occurrence: Cobalt carbides are typically formed by carburization of cobalt or cobalt-containing catalysts in carbon monoxide, methane, or other carbon-bearing atmospheres at elevated temperatures. They can also be produced by chemical vapor deposition from carbon-containing precursors or by high-temperature treatment of cobalt powders with carbon sources. Under reaction conditions such as Fischer–Tropsch synthesis, cobalt carbide phases may appear in situ on supported cobalt catalysts and may persist as long as carbon activity remains high.

Properties and role in catalysis: Cobalt carbides are generally hard, refractory materials that can coexist with metallic cobalt under catalytic conditions. Their presence has been associated with changes in activity and selectivity in hydrocarbon synthesis and reforming reactions. The exact role of the carbide phase is debated: some studies identify cobalt carbide as an active phase, others view it as a transient intermediate that may convert back to metallic cobalt upon reduction or during reaction.

Cobaltcarbon materials are of interest for understanding carbide formation under industrial processing conditions and for potential effects on the performance of cobalt-based catalysts.