The effect of the precursor structure on the catalytic properties of the nickel—chromium catalysts of hydrogenation reactions

Abstract

The influence of the Ni 2+ /Cr 3+ ratio in the precursor compound on the formation of the catalyst structure and its transformation upon the thermal treatment and reductive activation in hydrogen was studied. The precursors with the cation ratio Ni 2+ /Cr 3+ = (2.3-3)/1 represent a homogeneous system of the stichtite type structure. The treatment of the precursors at T ~400 °C in an inert atmosphere forms a nanosized phase of the NiO type structure with the lattice parameter a = 4.186±0.005 Å. At 600 °С the lattice parameter of this phase decreases to the tabulated value (a = 4.177±0.005 Å). The phase of nickel chromite of the cubic spinel structure with the lattice parameter a = 8.320±0.005 Å is also observed. Hydrogen activation of the catalyst preheated at 300 °C in an inert gas leads to the formation of Ni 0 crystallites with a size of ~5.5 nm and a specific surface area of ~7.0 m 2 g -1 . This catalyst exhibits high activity and selectivity in benzene hydrogenation and preferential CO hydrogenation in the presence of CO 2 . The catalysts with the ratio Ni 2+ /Cr 3+ = 1/(2-3) containing nickel and chromium hydroxocarbonates as precursors are less active in the hydrogenation of benzene to cyclohexane.

Composite Ni/NiO-Cr2O3 Catalyst for Alkaline Hydrogen Evolution Reaction

“…Nickel chromite has appeared in the literature as a catalyst for NO x reduction 47 as well as benzene and CO hydrogenation. 48 So the spinel clearly has a high affinity for formation of gas phase H ads in thermal reactors. Furthermore, the literature on metal oxide stability shows that Cr 2 O 3 is one of the most difficult oxides to reduce as it exhibited no transition to metallic Cr in H 2 -TPR studies up to 800 °C.…”

Solution Combustion Synthesis of Nanostructured NiCr2O4 Spinel and Its Catalytic Activity in CO Oxidation

“…Among these, of especial interest is the copper chromite CuCr 2 O 4 catalyst that was found to accelerate the CO-to-CO 2 conversion even at temperatures of below 300°С [1][2][3]. Similarly, good catalytic behavior was also exhibited by nickel chromite NiCr 2 O 4 spinel [4,5].…”

Petrological factors controlling abiotic methane formation in mafic-ultramafic rocks

“…Due to environmental and economic potential of CO2 hydrogenation, there is an increasing interest on the FTT catalysts and their behaviour under various conditions (e.g. Koopman 1980, Bartholomew 1982, Goodwin 1986, Girardon et al, 2005, Botes et al, 2009, Simentsova et al, 2010, Argyle & Bartholomew 2015, Rytter & Holmen 2015, Aragao et al, 2018, Atzori et al, 2018, Auvray et al, 2018, Chen et al, 2018, Danghyan et al, 2018. Some of the commonest metals that have been tested for their catalytic activity include Ni (e.g.…”

“…Some of the commonest metals that have been tested for their catalytic activity include Ni (e.g. Bartholomew 1982, Simentsova et al, 2010, Argyle & Bartholomew 2015, Atzori et al, 2018, Auvray et al, 2018, Danghyan et al, 2018, Ru (e.g. Koopman 1980, Goodwin 1986, Yaccato et al, 2005, Wang et al, 2011, Schoder et al, 2013 and Co (e.g.…”

“…Key factors that may affect, increase or decrease, the catalytic performance (e.g. Koopman 1980, Bartholomew 1982, Beuther et al, 1983, Goodwin 1986, Krishnamoorthy et al, 2002, Girardon et al, 2005, Botes et al, 2009, Simentsova et al, 2010, Argyle & Bartholomew 2015, Rytter & Holmen 2015, Aragao et al, 2018, Atzori et al, 2018, Auvray et al, 2018, Chen et al, 2018, Danghyan et al, 2018, are summarised in Table 2.1: The above petrological analogues are only hypothetical and their potential imprints on natural rocks will be under investigation during this study. In this case, important insights on the petrological characteristics of peridotites and formation of methane will be extracted.…”