In situ formation of Ni(CO)4 contaminant during IR analyses using a metal-containing reaction cell

Abstract

The formation of ppm levels of volatile Ni(CO)₄ occurred in the presence of 1 kPa CO over a worn commercial cell used for diffuse reflectance FT-IR, but not on a more recent cell. The presence of Ni(CO)₄ led to nickel deposition on Au and Cu-based catalysts evidenced by the presence of specific Ni–CO IR bands. In contrast, no Ni–CO IR bands could be observed on plain silica, suggesting that specific sites are required to decompose Ni(CO)₄. The unambiguous evolution of the carbonyl signal on Au/SiO₂ could be used as a test to assess the presence of ppm levels of Ni(CO)₄ in in situ and operando IR cells.