Bimetallic nanocatalysts in mesoporous silica for steam reforming reactions to produce H2 for fuel cells

Bimetallic nanocatalysts in ordered MCM-41 mesoporous silica have been synthesized using a one-pot hydrothermal procedure. The catalysts have been characterized using N2 adsorption-desorption isotherms, X-ray diffraction, highresolution transmission electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric-differential scanning calorimetry techniques. The mesoporous silica support showed surface area of about 974 m2/g and average pore size of 2.8 nm while upon metal encapsulation they decreased to 775 m2/g and 2.16 nm, respectively. While the small angle XRD studies confirmed the ordered structure of the silica, the HRTEM studies show uniform distribution of the metallic nanoparticles in mesoporous silica. Initial studies of the bimetallic nanocatalysts showed excellent activity for methanol conversion (~97% for Pd-Co/MCM-41 vs ~ 40% for Co/MCM-41) and selectivity to hydrogen (~95% for Pd-Co/MCM-41 vs 81% for Co/MCM-41), compared to the MCM-41containing only Pd or Co metal. This result suggested a synergistic interaction between the bimetallic nanocatalysts which resulted in a high methanol conversion and superior selectivity compared to the catalysts containing individual metals. Further investigations are underway to observe the effect of metal loading and the weight ratio on CO selectivity, methanol conversion, and catalyst deactivation at different operating conditions. © 2014 WIT Press.