Effect of Ag-Addition on the Catalytic and Physicochemical Properties of Ni/ZrO₂ Catalyst in Oxy-Steam Reforming of CH₄ and LNG Processes

Abstract

This work presents, for the first time, the catalytic studies of bimetallic Ag-Ni catalysts in the oxy-steam reforming (OSR) of liquefied natural gas (LNG) to hydrogen generation. The physicochemical properties of monometallic Ni and bimetallic catalysts were investigated using various techniques, such as: BET, TPR-H2, TPD-NH3, XRD, TG and SEM-EDS. The catalytic studies showed that the promotion of 20% Ni/ZrO2 catalyst by silver (by 1 or 2 wt.%) improves the efficiency of the produced hydrogen in the oxy-steam reforming of LNG at high temperature. The promotional effect of silver on the reducibility of a Ni/ZrO2 catalyst has been proven. The interactions between Ag and Ni have been proven, and explain the catalytic activity of the catalysts in the investigated processes. TG-DTA-MS results obtained for the spent catalysts proved that the small addition of silver to monometallic nickel catalyst reduces the amount of the carbon deposit formed on the catalyst surface during the oxy-steam reforming of LNG process. Obtained results in this work confirmed that liquid natural gas processing may become an alternative to fossil fuels and confirmed the validity of the hydrogen production via oxy-steam reforming of LNG.

Keywords

• hydrogen production
• oxy-steam reforming of methane
• ZrO₂ support
• bimetallic Ag-Ni catalysts
• silver promotion
• nickel catalyst