Resumen del producto

Nickel-based catalysts are of great importance for the generation of hydrogen from natural gas. Within
this process, the conditions in which commercial NiO/Al2O3 is converted to Ni0/Al2O3 catalyst should
be further investigated. A widely used technique to identify Ni2+ reduction conditions and the different
compounds or types of particles in which this element is present is temperature-programmed reduction.
In this work, the type of nickel oxide particles occurring on Al2O3 and ZnO-Al2O3-based supports
were studied by different techniques, such as energy-dispersive X-ray spectroscopy, FTIR, the BET
method, X-ray diffraction (XRD), and Temperature Programmed Reduction (TPR). All materials
were evaluated in the water gas shift reaction (WGS), and the influence of their characteristics on the
catalytic activity was assessed. Solids were prepared at different temperatures and Ni/Zn molar ratios.
The results showed the presence of NiO in all materials, as well as the presence of ZnO, NiAl2O4,
and ZnAl2O4 in materials prepared at higher temperatures. In all the materials calcined at the lowest
temperature, the formation of NiO particles that fail to interact with the supports was prioritized.
As the calcination temperature increased, NiO aggregates were formed, which, to a greater degree,
interacted with the supports, whereby nickel aluminate was detected in all materials prepared at 750
°C. Zinc increased the selectivity but decreased specific surface area and activity through the WGS
reaction. The solid labeled AZ15-500 showed higher activity and selectivity, reaching values of 100%
for the water gas shift reaction.

Abstract del producto

Nickel-based catalysts are of great importance for the generation of hydrogen from natural gas. Within
this process, the conditions in which commercial NiO/Al2O3 is converted to Ni0/Al2O3 catalyst should
be further investigated. A widely used technique to identify Ni2+ reduction conditions and the different
compounds or types of particles in which this element is present is temperature-programmed reduction.
In this work, the type of nickel oxide particles occurring on Al2O3 and ZnO-Al2O3-based supports
were studied by different techniques, such as energy-dispersive X-ray spectroscopy, FTIR, the BET
method, X-ray diffraction (XRD), and Temperature Programmed Reduction (TPR). All materials
were evaluated in the water gas shift reaction (WGS), and the influence of their characteristics on the
catalytic activity was assessed. Solids were prepared at different temperatures and Ni/Zn molar ratios.
The results showed the presence of NiO in all materials, as well as the presence of ZnO, NiAl2O4,
and ZnAl2O4 in materials prepared at higher temperatures. In all the materials calcined at the lowest
temperature, the formation of NiO particles that fail to interact with the supports was prioritized.
As the calcination temperature increased, NiO aggregates were formed, which, to a greater degree,
interacted with the supports, whereby nickel aluminate was detected in all materials prepared at 750
°C. Zinc increased the selectivity but decreased specific surface area and activity through the WGS
reaction. The solid labeled AZ15-500 showed higher activity and selectivity, reaching values of 100%
for the water gas shift reaction.

Palabras clave

catalysis; NiO particles; temperature programmed reduction; temperature effect; water gas shift reaction