Tuning Metal–Support Interactions on Ni/Al2O3 Catalysts to Improve Catalytic Activity and Stability for Dry Reforming of Methane

Abstract

Ni-based catalysts supported on alumina derived from the pseudo-boehmite prepared by the impregnation method were employed for catalytic dry reforming of methane reaction at the temperature of 550–750 °C. The effect of calcination temperature on physicochemical properties such as the Ni dispersion, reduction degree, nickel crystallite sizes, and metal–support interaction of the catalysts was investigated. The characterization results show that increasing the catalyst calcination temperature leads to the formation of nickel-alumina spinel, which enhances the metal–support interaction and increases the reduction temperature. The nickel nanoparticle size decreases and the effective dispersion increases with the increasing calcination temperature from 450 °C to 750 °C due to the formation of nickel aluminate. The catalyst calcined at 750 °C exhibits the highest CH4 and CO2 conversion owing to the small Ni0 active sites and high Ni dispersion. In a 200 h stability test in dry reforming of methane at 700 °C, the Ni/Al2O3-750 catalyst exhibits excellent catalytic stability and anti-coking ability.

A Review on the Role of Amorphous Aluminum Compounds in Catalysis: Avenues of Investigation and Potential Application in Petrochemistry and Oil Refining

“…There are many methods for the synthesis of aluminum hydroxides, such as mechanochemical and thermochemical activation, precipitation, calcination of aluminum salts, hydrothermal treatment of aluminum oxides and hydroxides, and hydrolysis of organoaluminium compounds. Each method has its own advantages and disadvantages, which are described in detail in numerous scientific papers [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. However, the problem of formation of amorphous alumina compounds, which inevitably arise during the synthesis by all the given methods except hydrothermal treatment, has not yet been sufficiently investigated.…”

“…Aluminum oxide is widely used in the global petrochemical industry due to the diverse physical and chemical properties of its surface formed during synthesis. It is an adsorbent-catalyst and also a catalyst support for various petrochemical and oil refining processes [1][2][3][4][5][6][7][8]. Alumina is used as a support for oxide catalysts applied in the neutralization of industrial emissions, as well as in hydrogenation, hydrogenolysis, reforming, and hydrotreating catalysts, where the active components are Cr, Mo, Ni, W oxides or metals (Pt, Pd, Ni, etc.)…”

“…Alumina is used as a support for oxide catalysts applied in the neutralization of industrial emissions, as well as in hydrogenation, hydrogenolysis, reforming, and hydrotreating catalysts, where the active components are Cr, Mo, Ni, W oxides or metals (Pt, Pd, Ni, etc.) [2][3][4]6,7]. In the hydrogenation processes, in case of nickel catalysts, the thermal stability of alumina increases up to 600-700 • C which significantly expands the range of its applications [5].…”

“…However, γ-alumina is considered as an effective catalyst support that provides a combination of high performance and selectivity of hydrotreating processes. The supports have significant influence on the properties of the catalysts, and modification of the supports can improve the potential and efficiency of the catalysis [4]. The widespread use of γ-alumina (γ-Al 2 O 3 ) is due to the different surface properties, which depend on the synthesis conditions of aluminum oxide.…”

“…Aluminum oxide is widely used in petroleum chemistry and oil refining [1][2][3][4][5][6][7][8]. The most commonly used aluminum oxide is γ-Al 2 O 3 as a catalyst or a catalyst support.…”