NiRu catalysts supported on η-Al2O3 for selective methanation of CO in H2-rich gases

Abstract

Among the various methods for removing carbon monoxide (CO) from hydrogen-rich (H₂-rich) gases, carbon monoxide selective methanation (CO-SMET) has become one of the most effective ones, bringing considerable advantages in terms of performance, environmental sustainability and cost. A bimetallic NiRu/η-Al₂O₃ catalyst with Ni–Ru alloy phases was prepared and its performance in the removal of CO through a selective methanation process was examined in this study. Also, a comparison was made with the NiRu/γ-Al₂O₃ catalyst. The NiRu/η-Al₂O₃ catalyst demonstrated excellent CO-SMET performance, reducing the CO concentration to below 10 ppm with over 50% selectivity between 215 and 300 °C. Its excellent catalytic performance can be ascribed to numerous Ni active sites, increased oxygen vacancies, and more acidic sites. Additionally, the NiRu/η-Al₂O₃ catalyst had the ability to resist sintering because of the formation of Ni–Ru alloy on it. Moreover, it also exhibited good catalytic stability.