Radiocarbon laboratories using liquid scintillation counting depend on the availability of a catalyst for benzene synthesis. One of the two commonly used is a commercially available chromium-activated silica-alumina catalyst, PKN/D1. As this catalyst will no longer be produced, we have tested similar catalysts as possible replace-ments. We measured benzene purity by gas chromato-graphy and mass spectro-metry, and found that chromium endowment was crucial for a proper catalyst function-. The surface area of the catalyst also sig-nificantly affected benzene yield and purity. We also studied the effects of different reaction conditions of acetylene absorption and benzene desorption on benzene purity. A catalyst with half of the Cr endowment and doubled specific surface area created yield and purity compara-ble to PKN/D1.
[Radiocarbon Volume 37, Number 2, 1995]