Bimetallic Ni-Fe Supported by Gadolinium Doped Ceria (GDC) Catalyst for CO2 Methanation

Abstract

CO₂ conversion into fuels and high value-added chemical feedstocks, such as methane, has gained novel interest as a crucial process for further manufacturing multi-carbon products. Methane, CH₄, becomes a promising alternative for environmental and energy supply issues. Nickel-based catalysts were found to be very active and selective for CH₄ production. The use of promoter and support material to develop high activity, high selectivity, and durable catalysts for CO₂ methanation at low temperature is a challenge. Gadolinium-Doped Ceria (GDC) has been known as material for Solid Oxide Fuel Cell (SOFC) and Solid Oxide Electrolysis Cell (SOEC) due to higher ionic conductivity and lower operating temperatures. However, few researches have been done regarding to CO₂ methanation over GDC as catalyst support so far. In this present work, CO₂methanation was investigated over bimetallic Ni-Fe catalyst supported by GDC. The results showed that CH₄ production rate by using Ni-Fe/GDC catalyst was higher than that of GDC at all reaction temperatures carried on. Ni-Fe/GDC showed remarkable CH₄ production rate as of 17.73 mmol.g_cat⁻¹.h⁻¹ at 280 °C. No catalytic activity was produced by GDC catalyst only. The highest CO₂ conversion (46.50%) was observed at 280 °C, with almost 100% selectivity to CH₄. The turnover frequency (TOF) value of Ni-Fe/GDC (4529.32 h⁻¹) was the highest than that of Ni and common CO₂ methanation catalyst, Ni/Al₂O₃ catalysts at 280 °C, further displaying the outstanding low-temperature catalytic activity.