Enhancing CO2 Hydrogenation to Methane by Ni-Based Catalyst with V Species Using 3D-mesoporous KIT-6 as Support

Abstract

Using renewable H2 for CO2 hydrogenation to methane not only achieves CO2 utilization, but also mitigates the greenhouse effect. In this work, several Ni-based catalysts with V species using 3D-mesoporous KIT-6 (Korea Advanced Institute of Science and Technology, KIT) as support were prepared at different contents of NiO and V2O5. Small Ni nanoparticles with high dispersibility on 20Ni-0.5V/KIT-6 were identified by X-ray diffraction (XRD), TEM and hydrogen temperature-programmed desorption (H2-TPD) analysis, which promoted the production of more Ni active sites for enhancing catalytic activity for CO2 methanation. Moreover, TEM and hydrogen temperature-programmed reduction (H2-TPR) characterizations confirmed that a proper amount of Ni and V species was favorable to preserve the 3D-mesoporous structure and strengthen the interaction between active Ni and KIT-6. The synergistic effect between Ni and V could strengthen surface basicity to elevate the ability of CO2 activity on the 20Ni-0.5V/KIT-6. In addition, a strong interaction with the 3D-mesoporous structure allowed active Ni to be firmly anchored onto the catalyst surface, which was accountable for improving catalytic activity and stability. These results revealed that 20Ni-0.5V/KIT-6 was a catalyst with superior catalytic activity and stability, which was considered as a promising candidate for CO2 hydrogenation to methane.

Understanding Catalysis—A Simplified Simulation of Catalytic Reactors for CO2 Reduction

“…As a consequence, to obtain the results shown in Figure 7b we have modified the reactor parameter values from the methanol case (see Table 3). Again, our kinetic results are in qualitative agreement with the published data [39].…”

“…ChemEngineering 2020, 4, x; doi: FOR PEER REVIEW www.mdpi.com/journal/chemengineering are in qualitative agreement with the published data [39]. By taking the tube length Ltube to be a variable, one may use the computation scheme of Figure 6 to simulate the molar flow rates of the individual chemical components as a function of position along the reactor tubes (Figure 8).…”

Co-Precipitated Ni-Mg-Al Hydrotalcite-Derived Catalyst Promoted with Vanadium for CO2 Methanation

“…When used as promotor, vanadium is recognized as a potential CO 2 methanation catalyst. Thus vanadium was found to increase Ni dispersion, enhance H 2 uptake, and additionally, VOx provides an electronic effect that can promote the dissociation of CO in the methanation reaction [26][27][28][29]. In our previous study, Mg-Al-V hydrotalcites with a vanadium loading from 0 to 4 wt% were impregnated with nickel and subsequently used as catalysts for CO 2 methanation.…”

“…Electronic promoters such as molybdenum [23], iron [20], or cobalt [24] are responsible for increasing the electron density of the catalytic sites, consequently increasing the catalytic activity. Vanadium was found to be a promising catalytic solution for catalytic CO 2 utilizations [25][26][27][28][29]. For double-layered materials, vanadium can be introduced into the hydrotalcite structure both by interlayer doping or by layer doping.…”

Revealing the dependence of CO2 activation on hydrogen dissociation ability over supported nickel catalysts

“…Meanwhile, H 2 -TPD provides information on the performance of a catalyst on hydrogen adsorption and uptake. 17 The lack of a reliable approach to describe the H 2 dissociation ability and the subsequent impact on the reaction pathway has hampered the understanding of nickel catalysts for CO 2 hydrogenation. Herein, supported Ni/SiO 2 catalysts with varying Ni loadings from 10 to 40 wt.% are synthesized and thoroughly investigated with a series of in situ spectroscopic characterizations, temperature-programmed reduction/desorption (TPR/TPD) studies with carefully modified surface and steady-state kinetic analysis.…”