MMT-supported Ni/TiO2 nanocomposite for low temperature ethanol steam reforming toward hydrogen production

- Ni-incorporated MMT/TiO2 nanocatalyst tested for ethanol steam reforming to hydrogen.
- MMT increased Ni dispersion in Ni/TiO2 composite with improved yield and selectivity.
- H2 production depends on catalyst composition, particle size and reaction conditions.
- H2 yield over Ni/MMT-TiO2 composite was 1.5-fold more than using micro-particles.
- Nanostructured Ni/MMT-TiO2 gave prolong stability than micro-particles in ESR.

Ni/TiO2 nanoparticles dispersed on montmorillonite (MMT) clay with different sizes for selective ethanol steam reforming with regard to hydrogen production has been investigated. Ni/MMT-TiO2 nano-composite catalysts were prepared by a sol-gel assisted impregnation method. The samples were extensively characterized by X-ray diffraction (XRD), N2 adsorption-desorption, Fourier transfer infrared (FTIR) spectroscopy, scanning electron coupled with energy dispersive X-ray (SEM-EDX) spectroscopy and thermogravimetric analysis (TGA). While Ni content progressively promoted the activity of TiO2 toward ethanol conversion and H2 yield, modification with MMT controlled the crystal growth and produced anatase phase of delaminated MMT/TiO2 nanocomposite. Formation of a surface Ni-MMT phase in the modified Ni/MMT-TiO2 nanocomposite catalyst enhanced Ni-dispersion and reducibility. Various parameters concerning the effect of temperature, steam-to-ethanol (S/E) feed ratio, MMT loading and Ni-metal loading on the catalytic performance, were thoroughly studied. The optimal performance was achieved for 12 wt. % Ni/20 wt. % MMT-TiO2, achieving an ethanol conversion of 89% and a H2 yield of up to 55% at 500 °C. In addition, the Ni/MMT-TiO2 nano-composite catalyst possessed the excellent stability at the optimum temperature, over 20 h reaction time. The relative low cost, good activity and stability of MMT modified Ni/TiO2 catalyst offers for an economical and feasible route for production of renewable hydrogen from ethanol.

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