Highly efficient Ru/TiO₂ -NiAl mixed oxide catalysts for CO selective methanation in hydrogen-rich gas

Abstract

Summary Selective CO methanation (CO‐SMET) is viewed as an effective H2‐rich gas purification technique for proton exchange membrane fuel cells. In this work, improved composite‐supported Ru catalysts were developed for the CO‐SMET process. Mixed metal oxides (MMOs) obtained by calcination of layered double hydroxides precursor were used as an effective catalyst supports. After incorporation of TiO2, the resulting TiO2‐MMO composites were expected to have an enhanced catalytic performance. Therefore, a series of TiO2‐NiAl layered double hydroxides was successfully prepared via 1‐pot deposition method. After calcination, the derived TiO2‐NiAl MMO‐supported Ru catalysts obtained by impregnation method showed excellent catalytic performance for CO‐SMET reaction. The catalyst could deeply remove the CO outlet concentration (<10 ppm) with a high selectivity (>50%) over the wide low‐temperature window (175‐260°C). Furthermore, the catalyst also showed high stability with no deactivation during a long‐term durability test (120 h). Based on X‐ray diffraction, Fourier transform infrared, Raman, thermogravimetric differential scanning calorimetry, N2 adsorption‐desorption, temperature‐programmed reduction, scanning electron microscopy, and transmission electron microscopy analyses, the enhanced catalytic performance of the TiO2‐NiAl MMO‐supported Ru catalyst was found to be related to the higher dispersion of Ru nanoparticles, partially reduced NiO species, and the increased specific surface area and structural stability of the support. The facile synthesis strategy proposed herein may open a new window for the efficient production of high‐quality H2.

A Novel Hierarchical RuNi/Al2O3–Carbon Nanotubes/Ni Foam Catalyst for Selective Removal of CO in H2-Rich Fuels

“…11 Specifically, uniformly dispersed, thermally stable metal catalysts can be generated after calcination and reduction. 5,12 Nevertheless, the intrinsic low specific surface area (SSA) and preferential agglomeration of the LDH particles considerably affect their catalytic performance.…”

Zr‐promoted nickel‐rich spinel‐supported Ni catalysts with enhanced performance for selective CO methanation

“…First, 0.10 g catalyst was loaded in the center of the tube and was prereduced in situ at 500 C in 30 vol% H 2 /N 2 (30 mL/min) for 2 hours. Afterward, the feed gas composed of 1 vol% CO, 20 vol% CO 2 , and 79 vol% H 2 , which simulated an actual reformate gas on a dry basis, 4,6,9 was fed into the tube with a gas hourly space velocity of 7200 hours À1 . The investigated temperature window of catalytic performance tests was from 150 C to 340 C. Each experimental result showed a good carbon balance (>97%) for CO-SMET.…”

“…Currently, Ni-based catalysts supported on various materials have been extensively reported in CO-SMET. [7][8][9][10] In particular, Ni/Al 2 O 3 catalyst draws a lot of attention due to the large specific surface area, rich porosity, and excellent stability. 11,12 However, the spinel phase NiAl 2 O 4 is inevitably formed by active Ni and Al 2 O 3 and is hard to be reduced, 13 leading to a decreased amount of active Ni and low catalytic performance.…”

“…Currently, Ni‐based catalysts supported on various materials have been extensively reported in CO‐SMET 7‐10 . In particular, Ni/Al 2 O 3 catalyst draws a lot of attention due to the large specific surface area, rich porosity, and excellent stability 11,12 .…”

A methanol fuel processing system with methanol steam reforming and CO selective methanation modules for PEMFC application

“…Testing results showed that CO conversion can reach up to 100% at about 200°C and hydrogen consumption could be lower than 5%. Ping et al 26 developed a composite‐supported Ru catalyst for selective CO methanation. The catalyst could deeply remove the CO concentration (<10 ppm) with a high selectivity (>50%) over the wide low‐temperature window (175°C‐260°C).…”