Mechanism Of Water-gas Shift Reaction Research Articles

Oxygen vacancies promoted hydrogen production from methanol aqueous phase reforming over MgAl−LDHs supported plasmonic Ru nanoparticles catalyst

Catalytic aqueous phase reforming of methanol is a promising process for the sustainable hydrogen production. The search for highly efficient heterogeneous catalyst is a topic of interest. Herein, we report oxygen vacancies enriched MgAl−LDHs supported plasmonic Ru nanoparticles catalyst exhibit excellent photocatalytic performance for efficient hydrogen production at 150 ºC under light irradiation. Characterizations demonstrate abundant oxygen vacancies are introduced into MgAl−LDHs via “memory effect”. The local electron transfer from oxygen vacancies of the MgAl−LDHs to the Ru nanoparticles leading the formation of electron-rich Ru species, which promote the dehydrogenation of methanol under light irradiation. In situ DRIFTS demonstrated a redox mechanism of water-gas shift reaction due to the existence of oxygen vacancies, which resulted a faster hydrogen production rate. This work displays a facile strategy for synthesis of oxygen vacancies rich LDH supported metal nanoparticles catalysts and deep understanding into the pathway and mechanism toward the effective hydrogen production.

Theoretical insight into the promotion effect of potassium additive on the water-gas shift reaction over low-coordinated Au catalysts.

How to elucidate the effect of alkali metal promoters on gold-catalyzed water-gas shift reaction intrinsically remains a challenging, because that the complex synergy effects such as strong metal-support interactions, interfacial effects, and charge transfer of supported metal catalysts makes people difficulty in the understanding the alkali promotion phenomenon in nature. Herein, we report a systematically study of whole water-gas shift reaction mechanism on pure and the K-modified defected-Au(211) (i.e., by removing one surface Au atom from perfect Au(211) and make one model with the Au-Au coordination number is six) by using the microkinetic modeling based on first principles. Our results indicate that the presence of K can increase the adsorption ability of oxygen-containing species via the attractive coulomb interaction, has no significant effect on the adsorption of H species, but inhibits the adsorption of CO due to the steric effect. K promoter stabilizes the water adsorption by ~0.3 eV, which results in one order increasing of whole reaction rate. Interestingly, the strong promotion effect of the K can be assigned to the significant direct space interaction between K and the adsorbate H2O* through the inducted electric field, which can be further confirmed by the posed negative electric field on the unpromoted D-Au(211). Microkinetic modeling results revealed that the carboxyl mechanism is the most likely to occur, redox mechanism is the next one, and the formate mechanism is the least likely to occur. For different kinds of alkali metal additives, the adsorption strength of water molecules gradually weakens from Li to Cs, but Na shows the best promoter behavior at the low temperature. By considering the effect of K contents on the reactivity of water-gas shift reaction, we found that the K with the medium coverage (~0.2~0.3 ML) has the strongest promoting effect. It is expected that the conclusion of this work can be extended to other WGSR catalytic systems like Cu(or Pt). All calculations were performed by using the plane-wave based periodic method implemented in Vienna ab initio simulation package (VASP, version 5.4.4), where the ionic cores are described by the projector augmented wave (PAW) method. The exchange and correlation energies were computed using the Perdew, Burke and Ernzerhof functional with the vdw correction (PBE-D3). The transition states (TSs) were searched using the climbing image nudged elastic band (CI-NEB) method. Some electronic structure properties like work function was predicated by the DS-PAW software. Microkinetic simulation was carried out using MKMCXX software.

Water gas shift reaction mechanism with copper slag as heat carrier and catalyst

Researchers in related fields are concentrating on the use of metallurgical slag waste heat to deliver stable heat for the pyrolysis or gasification of carbon–based materials. The key technology to achieve the clean utilization of coal is coal gasification. An important challenge for the technology is how to increase the amount of H2 in the mixture while decreasing the energy consumption of the gasification process. The typical temperature of copper slag, a typical iron–rich metallurgical slag, is 1300 °C. Relevant studies have demonstrated that copper slag can increase H2 production and support the water gas shift (WGS) reaction in addition to providing stable heat for coal gasification. The largest contribution of copper slag to the catalytic effect of the WGS reaction is demonstrated by the density functional theory (DFT) calculations, which reveal that the presence of copper slag lowers the energy barrier of H2O molecules dissociation from 6.57 eV to 4.61 eV. Additionally, the reduction in the CO2 formation process on the copper slag surface from 4.92 eV to 3.94 eV encouraged CO2 formation. This explains how the WGS reaction, which is catalyzed by copper slag acting as a heat carrier during the pulverized coal–vapor gasification process, works.

Theoretical study on water gas shift mechanism on MoS2 supported single transition metal M (M=Co, Ni, Cu) catalysts

In this paper, a two-dimensional M/MoS2 material system was constructed by supporting transition metal atoms M (M=Co, Ni, Cu) on the surface of MoS2. The structural properties, molecular adsorption and the reaction mechanism for water gas shift reaction (WGSR) were investigated based on DFT calculation. Compared with pristine MoS2, doping transition metal can make M/MoS2 more stable because the charge transfer between metal and MoS2 increases the polarization of Mo and S. The adsorption performance is significantly improved, which is conducive to the forward progress of the reaction. The band gap of materials is narrowed, which motivates MoS2 transforms to metal phase. The supporting metal can increase the charge transfer and the number of active sites in the system, which can effectively reduce the reaction energy barrier of WGS and improve the catalytic activity. The most potential WGSR mechanism of the three materials is the association mechanism, in which the HCOO* intermediate plays the leading role.

Direct identification of the carbonate intermediate during water-gas shift reaction at Pt-NiO interfaces using surface-enhanced Raman spectroscopy

Noble metal-reducible oxide interfaces have been regarded as one of the most active sites for water-gas shift reaction. However, the molecular reaction mechanism of water-gas shift reaction at these interfaces still remains unclear. Herein, water-gas shift reaction at Pt-NiO interfaces has been in-situ explored using surface-enhanced Raman spectroscopy by construction of Au@Pt@NiO nanostructures. Direct Raman spectroscopic evidence demonstrates that water-gas shift reaction at Pt-NiO interfaces proceeds via an associative mechanism with the carbonate species as a key intermediate. The carbonate species is generated through the reaction of adsorbed CO with gaseous water, and its decomposition is a slow step in water-gas shift reaction. Moreover, the Pt-NiO interfaces would promote the formation of this carbonate intermediate, thus leading to a higher activity compared with pure Pt. This spectral information deepens the fundamental understanding of the reaction mechanism of water-gas shift reaction, which would promote the design of more efficient catalysts. Direct spectroscopic evidence of the carbonate intermediate and its evolution during water-gas shift reaction at Pt-NiO interfaces is obtained using surface-enhanced Raman spectroscopy, based on which the reaction mechanism is then proposed.

Mechanism Investigations on Water Gas Shift Reaction over Cu(111), Cu(100), and Cu(211) Surfaces.

Cu-based catalysts are commonly applied in low-temperature water gas shift (WGS) reactions, owing to their low cost and high catalytic activity. The influence of different Cu surfaces on catalytic activity and mechanism over the WGS reaction remains unclear. In this work, the effect of different structures of surfaces on the WGS mechanism is studied using density functional theory (DFT). Three surface terminations (Cu(100), Cu(111), and Cu(211)) of Cu are considered, and the coordination number (CN) of the active Cu site is in the range from 7 to 9. The most stable surface is Cu(211). Then, d-band center values are calculated, which decrease in the following sequence: Cu(211) > Cu(100) > Cu(111). This shows that d-band center values decrease with increasing coordination number. The increase in the centers of the d-band leads to an increase in the adsorption strength of CO and H2O adsorbates, which is in line with the theory of the d-band center. In addition, the further calculated mechanism for WGS reaction over three different Cu surfaces illustrates that the carboxyl path is the most favorable mechanism, and the rate-determining step is H2O dissociation. Cu(211) shows excellent WGS catalytic performance, better than the Cu(100) and Cu(111) surfaces. This work provides theoretical insights into the rational design of highly active Cu-based catalysts toward WGS reaction.

Probing the mechanism of H2 production in water gas shift reaction over Ce-modified CaO: A DFT study

The sorption-enhanced water gas shift reaction (WGSR) using CaO-based materials is a promising technology for H2 production, which can be further improved with the Ce-modified CaO material. However, the underlying mechanism for WGSR with the assistance of Ce-modified CaO remains unclear. A Ce-modified CaO periodic slab model was established in this paper, and the density functional theory (DFT) simulations for WGSR characteristics on Ce-modified CaO surface were performed. The results demonstrate that the Ce-modified CaO exhibits higher electron density, and the electron transfer between Ce and adjacent O is observed. The Ce doping obliterates the band gap of CaO, and the Fermi level is penetrated by O 2p orbit of Ce-modified CaO. The intermediates involved in WGSR exhibit obvious mutual promotion for co-adsorption with Ce-modification, and the H2 desorption is facilitated by the absorbed CO2. Ce doping avoids the generation of an additional intermediate, and the energy barriers of H2 generation and CO2 adsorption are reduced. The rate-limiting step on Ce-modified CaO is altered to the cleavage of O–H bond and formation of CO2 radical, and the energy barrier is 2.15 eV, which is 34.6% lower than that on CaO. Therefore, the enhancement mechanism on H2 production in WGSR resulted by Ce-modified CaO was determined.

First-principles study on the mechanism of water-gas shift reaction on the Fe3O4 (111)-Fetet1

Water-gas shift reaction (WGSR) is an important means for the production of H2 in industry, but the understanding of high-temperature WGSR on iron oxide catalysts is not sufficient, especially the relationship between crystal planes of Fe3O4 and reaction mechanisms and activity. In this paper, the three mechanisms of WGSR on Fe3O4 (111)-Fetet1 have been systematically studied by the density functional theory (DFT) considering spin polarization, and the whole reaction paths of three mechanisms were calculated in detail. The results indicate that association mechanism and regeneration mechanism are coexisted, and the effective energy barrier of the association mechanism is the lowest of 0.45 eV. For the step of H2 formation, the activity is affected by the coverage of surface *H and the O defects concentration. High surface H coverage and a lot of O defects are beneficial to the H2 formation. These results are helpful for further understanding the mechanism of WGSR on Fe3O4 catalyst.

Mechanisms of CO2 reduction into CO and formic acid on Fe (100): a DFT study

Understanding the mechanism of CO2 reduction on iron is crucial for the design of more efficient and cheaper iron electrocatalyst for CO2 conversion. In the present study, we have employed spin-polarized density functional theory calculations within the generalized gradient approximation (DFT-GGA) to elucidate the mechanism of CO2 reduction into carbon monoxide and formic acid on the Fe (100) facet. We also sort to understand the transformations of the other isomers of adsorbed CO2 on iron as earlier mechanistic studies are centred on the transformations of the C2v geometry alone and not the other possible conformations i.e., flip-C2v and Cs modes. Two alternative reduction routes were considered i.e., the direct CO2 dissociation against the hydrogen-assisted CO2 transformation through formate and carboxylate into CO and formic acid. Our results show that CO2 in the C2v mode is the precursor to the formation of both products i.e., CO and formic acid. Both the formation and transformation of CO2 in the Cs and flip-C2v is challenging kinetically and thermodynamically compared to the C2v mode. The formic acid formation is favoured over CO via the reverse water gas shift reaction mechanism on Fe (100). Both formic acid formation and CO formation will proceed via the carboxylate intermediate since formate is a stable intermediate whose transformation into formic acid is challenging both kinetically and thermodynamically.Graphic abstract

Insights into the catalytic activity of trimetallic Al/Zn/Cu surfaces for the water gas shift reaction

In this study, we evaluated the performance of Al/Zn/Cu trimetallic catalysts for the water gas shift (WGS) reaction by Density Functional Theory (DFT) calculations. A previous DFT-based study comparing the activity of a large series of trimetallic surfaces towards the catalysis of water dissociation showed that the (AlZn)s@Cu(111) surface is likely the most active catalysts for the WGS reaction. Note that, the water dissociation is the rate-determining step of the WGS reaction on copper surfaces. Therefore, in this work we carried out a systematic study of all possible WGS reaction steps on such catalyst model surface. The most plausible WGS reaction mechanism on the trimetallic surface was inferred by comparing the activation energies, reaction energies and rate constants computed for its different reaction steps. The latter demonstrated that the WGS evolves on this trimetallic surface following an associative mechanism through the carboxyl intermediary, which is dehydrogenated on the surface, assisted by a hydroxyl, to produce CO2. The other WGS reaction product, this is H2, is obtained by the combination of hydrogen atoms from the water dissociation. The activation energy barriers obtained for the WGS reaction steps on that trimetallic surface are always lower than the adsorption energy of the correspondent reactants, indicating that desorption cannot compete with the catalytic process and also, that the trimetallic Al/Zn/Cu surface should be very reactive for the WGS reaction catalysis. Overall the results of this study allowed us to suggest that the active phase of commonly employed commercial catalyst based on Cu/ZnO/Al2O3 might embody a trimetallic alloy of Al/Zn/Cu.

Revisiting magnesium oxide to boost hydrogen production via water-gas shift reaction: Mechanistic study to economic evaluation

Herein, we report the use of a MgCeOx-supported Cu (MgCuCe) catalyst with a unique bead structure to augment the water-gas shift (WGS) reaction. The MgCuCe catalyst exhibited an exceptionally high reaction rate of 83 μmol g−1 s‒1 at 300 °C, compared with that without MgO (30 μmol g−1 s‒1). Very few studies have focused on MgO-supported catalysts owing to the reports on the inferior activity of MgO. However, this paper reports unprecedented enhancements by introducing MgO and illustrates the WGS reaction mechanism: (1) numerous defects promoted water dissociation and subsequent associative mechanism; (2) the labile oxygen in MgO participated in redox mechanisms. The hydrogen production cost realized due to the use of the MgCuCe was 0.63 USD/kg H2, which is lower than that achieved by using commercial and CeO2-supported catalysts. This study paves the way for exploiting earth-abundant MgO in developing efficient catalysts and contributes to reducing H2 production costs.

Large Impact of Approximate Exchange-Correlation Functionals on Modeling the Water Gas Shift Reaction on Copper

We investigate the water gas shift reaction (WGSR) on copper using three levels of exchange-correlation (XC) functionals of increasing complexity: the Perdew–Burke–Ernzerhof (PBE) functional, the Heyd–Scuseria–Ernzerhof (HSE) hybrid functional, and the exact exchange plus the random phase approximation (RPA) correlation functional. We show that DFT predictions for the kinetics of the WGSR strongly depend on the choice of XC functionals. It is important to have accurate CO adsorption energy. Due to PBE’s overestimation of CO’s adsorption energy, it predicts small free surface and a negative (incorrect) reaction order for CO. HSE and RPA largely avoid such overestimation and predict large free surface and positive reaction orders for CO. The key finding in this work is that the prediction for the WGSR mechanism also depends on the choice of XC functionals. PBE and HSE predict the carboxyl mechanism, while RPA predicts that both redox and carboxyl mechanisms are important. These results suggest that caution should be paid when using approximate XC functionals to model heterogeneous catalysis (such as the WGSR investigated here) in which several mechanisms compete. In addition, we also observed one problem for RPA: It underestimates the overall WGSR energy and predicts a negative reaction order for CO2. In addition, we examine formate’s role in the WGSR over copper. Both DFT and previous experiments suggest that formate does not participate much in the reaction and cannot cause a negative reaction for CO2 for the WGSR over copper.

Evaluation of the Oxygen Mobility in CePO4-Supported Catalysts: Mechanistic Implications on the Water–Gas Shift Reaction

The hexagonal and monoclinic phases of CePO4 have been demonstrated to be excellent catalytic supports for Pt-based water–gas shift (WGS) catalysts. Consequently, the elucidation of the WGS reaction mechanism in these materials constitutes a fundamental aspect in order to explain their catalytic behavior. Because the observed WGS reaction path is closely related to the absence or presence of oxygen vacancies in the support, the study of the oxygen mobility in these solids constitutes a key factor for the understanding of the structure of the materials and its influence on the reaction mechanism. In this study, the oxygen mobility in CePO4 supports and the corresponding Pt catalysts has been evaluated by means of isotopic exchange experiments using 18O2 and C18O2 as probe molecules. Results demonstrate that the evaluated solids present a low exchange activity when 18O2 is used, indicating the absence of oxygen vacancies in these solids, thus suggesting a poor influence of the WGS redox mechanism. On the contrary, a high oxygen exchange activity is observed using C18O2, demonstrating that the exchange in these materials takes place through the formation of carbonate-like intermediates, thus suggesting the associative mechanism of the WGS reaction as the preferred path in these solids. Operando diffuse reflectance infrared spectroscopy experiments under WGS reaction conditions confirm these results, proving that the WGS reaction in the studied materials takes place through a formate-mediated associative mechanism.

Dual Metal Active Sites in an Ir1/FeOxSingle‐Atom Catalyst: A Redox Mechanism for the Water‐Gas Shift Reaction

AbstractHerein, we report a theoretical and experimental study of the water‐gas shift (WGS) reaction on Ir1/FeOxsingle‐atom catalysts. Water dissociates to OH* on the Ir1single atom and H* on the first‐neighbour O atom bonded with a Fe site. The adsorbed CO on Ir1reacts with another adjacent O atom to produce CO2, yielding an oxygen vacancy (Ovac). Then, the formation of H2becomes feasible due to migration of H from adsorbed OH* toward Ir1and its subsequent reaction with another H*. The interaction of Ir1and the second‐neighbouring Fe species demonstrates a new WGS pathway featured by electron transfer at the active site from Fe3+−O⋅⋅⋅Ir2+−Ovacto Fe2+−Ovac⋅⋅⋅Ir3+−O with the involvement of Ovac. The redox mechanism for WGS reaction through a dual metal active site (DMAS) is different from the conventional associative mechanism with the formation of formate or carboxyl intermediates. The proposed new reaction mechanism is corroborated by the experimental results with Ir1/FeOxfor sequential production of CO2and H2.

Dual Metal Active Sites in an Ir1 /FeOx Single-Atom Catalyst: A Redox Mechanism for the Water-Gas Shift Reaction.

Herein, we report a theoretical and experimental study of the water-gas shift (WGS) reaction on Ir1 /FeOx single-atom catalysts. Water dissociates to OH* on the Ir1 single atom and H* on the first-neighbour O atom bonded with a Fe site. The adsorbed CO on Ir1 reacts with another adjacent O atom to produce CO2 , yielding an oxygen vacancy (Ovac ). Then, the formation of H2 becomes feasible due to migration of H from adsorbed OH* toward Ir1 and its subsequent reaction with another H*. The interaction of Ir1 and the second-neighbouring Fe species demonstrates a new WGS pathway featured by electron transfer at the active site from Fe3+ -O⋅⋅⋅Ir2+ -Ovac to Fe2+ -Ovac ⋅⋅⋅Ir3+ -O with the involvement of Ovac . The redox mechanism for WGS reaction through a dual metal active site (DMAS) is different from the conventional associative mechanism with the formation of formate or carboxyl intermediates. The proposed new reaction mechanism is corroborated by the experimental results with Ir1 /FeOx for sequential production of CO2 and H2 .

Water-gas shift reaction catalyzed by Au32M6 (M = Cu, Pt, Pd, Rh, Ir) core-shell nanoclusters: A density functional theory study

In this paper, the mechanism of water-gas shift reaction (WGSR) on Au32M6 (M = Cu, Pt, Pd, Rh, Ir) core-shell nanoclusters was investigated by density functional theory (DFT). The result shows that the unique synergistic effect in the core-shell structure of Au32M6 has a significant effect on the activity of the catalyst. Compared with the Au38 nanocluster, in the case of Au32M6, the charge transfer between the M6 core and the Au32 shell is larger after the formation of the core-shell nanocluster. The calculation of the binding energy indicates that the Au32M6 core-shell nanoclusters is more stable than Au38 nanocluster. The parameters for the center of d-band show that d-orbital electrons of Au32Pd6 nanoclusters closer to the Fermi level than other nanoclusters, which indicates the Au32Pd6 nanocluster have better electron activity. In addition, we also found out the minimum energy pathways (MEP) of each nanocluster based on the adsorption investigation of various species on Au32M6 in the WGSR. The calculation results show that Au32Pd6 nanocluster exhibits excellent catalytic activity for WGSR, the reaction pathway was ER 1 → ER 4 → ER 5-b → ER 6.

Elucidation of the Reaction Mechanism for High-Temperature Water Gas Shift over an Industrial-Type Copper-Chromium-Iron Oxide Catalyst.

The water gas shift (WGS) reaction is of paramount importance for the chemical industry, as it constitutes, coupled with methane reforming, the main industrial route to produce hydrogen. Copper-chromium-iron oxide-based catalysts have been widely used for the high-temperature WGS reaction industrially. The WGS reaction mechanism by the CuCrFeO x catalyst has been debated for years, mainly between a "redox" mechanism involving the participation of atomic oxygen from the catalyst and an "associative" mechanism proceeding via a surface formate-like intermediate. In the present work, advanced in situ characterization techniques (infrared spectroscopy, temperature-programmed surface reaction (TPSR), near-ambient pressure XPS (NAP-XPS), and inelastic neutron scattering (INS)) were applied to determine the nature of the catalyst surface and identify surface intermediate species under WGS reaction conditions. The surface of the CuCrFeO x catalyst is found to be dynamic and becomes partially reduced under WGS reaction conditions, forming metallic Cu nanoparticles on Fe3O4. Neither in situ IR not INS spectroscopy detect the presence of surface formate species during WGS. TPSR experiments demonstrate that the evolution of CO2 and H2 from the CO/H2O reactants follows different kinetics than the evolution of CO2 and H2 from HCOOH decomposition (molecule mimicking the associative mechanism). Steady-state isotopic transient kinetic analysis (SSITKA) (CO + H216O → CO + H218O) exhibited significant 16O/18O scrambling, characteristic of a redox mechanism. Computed activation energies for elementary steps for the redox and associative mechanism by density functional theory (DFT) simulations indicate that the redox mechanism is favored over the associative mechanism. The combined spectroscopic, computational, and kinetic evidence in the present study finally resolves the WGS reaction mechanism on the industrial-type high-temperature CuCrFeO x catalyst that is shown to proceed via the redox mechanism.

CO-ADSORPTION OF CO, H2O AND MECHANISM OF WATER GAS SHIFT REACTION ON ZnO CATALYST SURFACE: A DENSITY FUNCTIONAL THEORY STUDY

In this works, co-adsorption of CO, H2O and mechanism calculations of water gas shift reaction (WGSR) on ZnOcatalyst surface using the density functional theory (DFT) was investigated. Performing the most stable site of co-adsorbed CO and H2O with configuration and adsorption energy on the catalyst surface were indentified. The carboxyl mechanism of WGSR was proposed and examined then. Based on carboxyl mechanism, the beginning of reaction pathway with the most stable co-adsorbed CO and H2O configuration as initial state on ZnOcatalyst surface was considered. The resulted calculations pointed out that the pathway of WGSR mechanisms on the surface was favorable kinetically with rate-determining steps of 1.56 eV.

Stochastic surface walking reaction sampling for resolving heterogeneous catalytic reaction network: A revisit to the mechanism of water-gas shift reaction on Cu

Heterogeneous catalytic reactions on surface and interfaces are renowned for ample intermediate adsorbates and complex reaction networks. The common practice to reveal the reaction mechanism is via theoretical computation, which locates all likely transition states based on the pre-guessed reaction mechanism. Here we develop a new theoretical method, namely, stochastic surface walking (SSW)-Cat method, to resolve the lowest energy reaction pathway of heterogeneous catalytic reactions, which combines our recently developed SSW global structure optimization and SSW reaction sampling. The SSW-Cat is automated and massively parallel, taking a rough reaction pattern as input to guide reaction search. We present the detailed algorithm, discuss the key features, and demonstrate the efficiency in a model catalytic reaction, water-gas shift reaction on Cu(111) (CO + H2O → CO2 + H2). The SSW-Cat simulation shows that water dissociation is the rate-determining step and formic acid (HCOOH) is the kinetically favorable product, instead of the observed final products, CO2 and H2. It implies that CO2 and H2 are secondary products from further decomposition of HCOOH at high temperatures. Being a general purpose tool for reaction prediction, the SSW-Cat may be utilized for rational catalyst design via large-scale computations.

A comprehensive study of kinetics mechanism of Fischer-Tropsch synthesis over cobalt-based catalyst

A comprehensive kinetics study of Fischer-Tropsch (FT) synthesis mechanism was investigated over an in-house 37% Co-based catalyst on a SiO2 support. A series of combined FT and water gas shift (WGS) reaction mechanisms were developed in order to calibrate the model at twelve different operating conditions. Two different approaches were used to develop a model for the FT synthesis reaction network. The first was based on an empirical approach; whereas the second approach explained the novel mechanistic details of FT kinetics. In the former, the rate equations were derived by power-law rate expressions, while in the latter the rate equations were derived by the Langmuir–Hinshelwood-Hougen-Watson (LHHW) rate theory. The limitations of power-law rate model were highlighted for the applications that wider range of operating conditions has to be selected. In contrast the advantages of LHHW for predicting a wider range of operating conditions were underlined. A comprehensive plausible mechanism-derived FT kinetics models with eight elementary reaction pathways along with seven WGS kinetics models were developed. Such reaction networks were investigated to fit and validate against the newly obtained experimental results which can be used as a key tool to emphasise the most significant facts of FT synthesis catalysis and chemistry. Model validation was carried out subsequent to completion of the model calibration and the estimation of proper kinetic parameters. The overall purpose of the validation study was to ensure that the model provides a robust and realistic assessment of all the parameters. In order to ensure model is precise to an appropriate level, the model was assessed against experimental data at four different operating conditions. The results obtained from kinetic study were compared to the most recent findings that have been reported in literature. It was shown that the novel developed kinetic model based on a combination of alkyl/alkenyl mechanism for FT reactions (for production of n-paraffins and α-olefins) along with formate mechanism for WGS reaction can provide the most accurate predictions.