The Determination of Mo,Co,and Ni in Hydrodesulfurization Catalysts by Atomic Absorption Spectroscopy

Abstract

An atomic absorption technique was adopted to analyze hydrodesulfurization catalysts for Mo, Co, and/or Ni. After dissolution of the catalyst by sulfuric acid and hydrofluoric acid, the analysis for Mo and Co is determined using N₂O-C₂H₂ flames and Ni is determined using air-C₂H₂. It was shown that the Al (80 to 85%) in the sample from the γ-alumina support of the catalyst enhanced the Mo and Co absorption signals in the N₂O-C₂H₂ flame while no enhancement was seen for the Ni absorption signal when the cooler air-C₂H₂ flame was employed. Eleven commercial catalysts with information from the manufacturers on Mo, Co, and/or Ni content were analyzed by this method. The results were also in agreement with two other activation analysis methods. The relative standard deviation ranged from 1.5 to 2.5%.