Mechanism Of Methanol Synthesis Research Articles

Mechanism of methanol synthesis from CO2 on Cu/CeO2 and Cu/W-CeO2: a DFT investigation into the nature of W-doping

The modified text: DFT calculations indicate that W-doping changes the reaction of methanol synthesis from CO2 at the Cu8/CeO2-Ov from the RWGS + CO hydrogenation pathway to the formate pathway by weakening the interaction of Cu–Oup but enhancing the C–Odown bond.

Mechanism of Methanol Synthesis from CO2 Hydrogenation over Cu/γ-Al2O3 Interface: Influences of Surface Hydroxylation

The adsorption and hydrogenation of carbon dioxide on γ-Al2O3(110) surface-supported copper clusters of different sizes are investigated using density functional theory calculations. Our results show that the activation of CO2 is most obvious at the Cu/γ-Al2O3 interface containing the size-selected Cu4 cluster. It is interesting that the CO2 activation is more pronounced at the partially hydroxyl-covered interface. The catalytic mechanisms of CO2 conversion to methanol at the dry and hydroxylated Cu4/γ-Al2O3 interfaces via the formate route and the pathway initiated through the hydrogenation of carbon monoxide produced by the reverse water–gas shift reaction are further explored. On both interfaces, the formate pathway is identified as the preferred reaction pathway, in which the hydrogenation of HCOO to H2COO is the rate-limiting step (RLS). However, since the surface OH group can act as a hydrogen source in some elementary reactions, unlike the dry surface, the production of H2COOH species along the formate pathway is found at the hydroxylated interface. In addition, the introduction of OH at the interface leads to an increase in the kinetic barrier of the RLS, indicating that surface hydroxylation has a negative effect on the catalytic activity of CO2 conversion to CH3OH at the Cu/γ-Al2O3 interface.

Development of a method and algorithm for calculating the equilibrium of methanol synthesis under medium pressure

The object of research is the synthesis of methanol under medium pressure, and the subject of research is the calculation of the equilibrium composition. A method and an algorithm for calculating the equilibrium composition of products are proposed. Calculations have been carried out using two mechanisms of methanol synthesis. First of all, the first approach to the mechanism of methanol synthesis was applied, which provides for the formation of methanol from a mixture of carbon oxides and hydrogen by the simultaneous reaction of methanol synthesis from carbon monoxide (IV) and steam reforming of carbon monoxide (II). The poor convergence of the system of two equations on the basis of this interaction mechanism is established, which complicates the selection of initial approximations and the choice of a real solution. At the second stage, the mechanism of the formation of methanol from carbon monoxide (II) with the simultaneous flow of steam reforming of CO in the opposite direction is considered. The degree of the equation describing the dependence of the equilibrium constant on the partial pressures of the reactants decreases in comparison with the first approach and causes much better convergence when solving the system of two equations. The use of a coefficient that takes into account the effect of pressure on the value of the equilibrium constant is proposed, and its dependence on temperature is approximated. The developed algorithm is implemented in MathCAD, while the relative maximum deviation for methanol is 8.53 %. The third approach is to use two coefficients that adjust the equilibrium constant depending on pressure. In this case, the relative maximum deviation of methanol is 16.25 %. The program according to the proposed algorithm takes into account the multiplicity of the initial data, namely the possibility of varying the composition of the initial mixture, pressure and temperature. The calculation was carried out according to the initial data of industrial implementation of methanol synthesis. Comparison of the equilibrium concentration of methanol with the real one at the outlet of the synthesis column established the degree of equilibrium reaching 39.4 %, which indicates the presence of a reserve of methanol synthesis and the possibility of increasing the practical yield of methanol.

Deciphering Mn modulated structure-activity interplay and rational statistical analysis for CO2 rich syngas hydrogenation to clean methanol

Methanol produced from chemical transformation of coal derived CO2 rich syngas can be a sustainable replacement for conventional crude oil based fuels with an impressive feature of reducing greenhouse gas emissions. Mostly industrial catalysts are promoted, however, lack of detailed insight into the mechanism of promotion has so far restricted the identification of non-precious promoter. In this work, a series of Cu–Zn–Mn oxide catalysts were synthesized by varying Mn loading from 0 to 30 mol% at pH near 7 and 70 °C via co-precipitation technique to elucidate the role of Mn-promoted malachite precursors in micro structural properties of catalyst. Investigation revealed that incorporating 20 mol% Mn (CuZn:Mn[0.2]) in malachite lattice resulted in better stabilization and dispersion of CuO domains owing to maximum dilution of Cu2+ ions as compared to other three analogous catalysts. Consequently, CuZn:Mn[0.2] catalyst unveiled ∼1.4-fold and ∼1.2-fold increase in CO conversion and methanol selectivity respectively as compared to the unpromoted catalyst. However, Mn loading beyond 20 mol% showed a detrimental effect on the catalytic efficiency due to dominant presence of an additional aurichalcite by-phase which revokes dilution of Cu2+ ions. Co-feeding CO2 in syngas improves dual active sites synergy (Cu0/Cu+) which helps in understanding catalytic mechanism of methanol synthesis. For best performing catalyst, statistically validated non-linear mathematical models were derived using response surface methodology along with central composite design. These models forecasted the correlations between process parameters as well as identified the relative contribution of each parameter. For maximising both methanol selectivity and CO conversion, desirability function predicted the optimum values of reaction temperature, pressure, and feed gas molar ratio (CO/CO2/H2) as 242 °C, 49 bar and 3 respectively. Under these conditions, 46% CO conversion and 93% methanol selectivity were obtained. Thus, the formulated coal to methanol process originating from catalyst design to optimization of process parameters paves the way for sustainable solutions referring to global “3E” issues, viz. energy, environment, and economic challenges.

Mechanism of Methanol Synthesis from CO2 Hydrogenation over Pt8/In2O3 Catalysts: A Combined Study on Density Functional Theory and Microkinetic Modeling

Mechanism of Methanol Synthesis from CO₂ Hydrogenation over Pt₈/In₂O₃ Catalysts: A Combined Study on Density Functional Theory and Microkinetic Modeling

Mechanism of CO2 hydrogenation to methanol on the W-doped Rh(111) surface unveiled by first-principles calculation

Understanding the mechanisms of CO2 hydrogenation on a specific catalyst is of profound significance for developing the high-efficient catalytic materials. Herein, first-principles calculation is performed to research the mechanisms of methanol synthesis from CO2 hydrogenation on tungsten (W)-doped Rh(111) catalyst. The optimal adsorption site, geometric parameters, and adsorption energy of each species are determined. The analysis of electronic structure reveals that CO2* is greatly activated on the W-doped Rh(111) surface due to the charge transfer and obvious orbital hybridization between them. Then, a descriptor is defined to preliminarily predict the reaction thermodynamics. Furthermore, the optimal reaction mechanism is determined by comparing the activation barriers and reaction energies of all elementary reactions. Compared with Rh(111), it can be found that the doping of W has a great hindrance to the elementary reactions in the RWGS and trans-COOH pathways, while the elementary reactions of the HCOO pathway are less affected. The optimal hydrogenation route on the W-doped Rh(111) surface is the HCOO pathway followed by CO2* → HCOO* → HCOOH* → H2COOH* → H2CO* → CH3O* → CH3OH*. The analysis of Mulliken charge shows that after the doping of W atoms, the modified electronic structure of Rh(111) is conducive to the conversion of CO2 and the generation of CH3OH.

Mechanism of CO2 hydrogenation over a Zr1–Cu single-atom catalyst

The reaction mechanisms of methanol synthesis from CO2 hydrogenation on a Zr1–Cu surface are investigated using density functional theory calculations.

Mechanism of methanol synthesis on Ni(110)

Planewave density functional theory (DFT-PW91) calculations are employed to study the methanol synthesis through CO2 and CO hydrogenation, as well as the two side reactions: the water gas shift (WGS) reaction and the formic acid formation, on Ni(110).

A DFT-based microkinetic study on methanol synthesis from CO2 hydrogenation over the In2O3 catalyst.

In this work, we performed density functional theory (DFT)-based microkinetic simulations to elucidate the reaction mechanism of methanol synthesis on two of the most stable facets of the cubic In2O3 (c-In2O3) catalyst, namely the (111) and (110) surfaces. Our DFT calculations show that for both surfaces, it is difficult for the H atom adsorbed at the remaining surface O atom around the O vacancy (Ov) active site to migrate to an O adsorbed at the Ov due to the very high energy barrier involved. In addition, we also find that the C-O bond in the bt-CO2* chemisorption structure can directly break to form CO with a lower energy barrier than that in its hydrogenation to the COOH* intermediate in the COOH route. However, our microkinetic simulations suggest that for both surfaces, CO2 deoxygenation to form CO in both pathways, namely the COOH and CO-O routes, are kinetically slower than methanol formation under typical steady state conditions assuming a CO2 conversion of 10% and a CO selectivity of 1%. Although these results agree with previous experimental observations at relatively low reaction temperature, where methanol formation dominates, they cannot explain the predominant formation of CO at relatively high reaction temperature. We tentatively attribute this to the simplicity of our microkinetic model as well as possible structural changes of the catalyst at relatively high reaction temperature. Furthermore, although the rate-determining step (RDS) from the degree of rate control (DRC) analysis is usually consistent with that judged from the DFT calculated energy barriers, for CO2 hydrogenation to methanol over the (111) surface, our DRC analysis suggests homolytic H2 dissociation to be the rate-controlling step, which is not apparent from the DFT-calculated energy barriers. This indicates that CO2 conversion and methanol selectivity over the (111) surface can be further enhanced if homolytic H2 dissociation can be accelerated for instance by introducing transition metal dopants as already shown by some experimental observations.

Insights into the methanol synthesis mechanism via CO2 hydrogenation over Cu-ZnO-ZrO2 catalysts: Effects of surfactant/Cu-Zn-Zr molar ratio

In this study, we evaluated aspects of the CO2 hydrogenation mechanism, correlating structure-activity relationships of Cu-ZnO-ZrO2 catalysts prepared by one-pot surfactant-assisted co-precipitation with different surfactant ratios. Identifying the CO2 hydrogenation pathway intermediates is key to controlling the reaction selectivity. Experimental evidence shows that the CO2 is dissociating into CO* and O* onto the surface of the Cu-ZnO-ZrO2 catalyst. The adsorption and dissociation of CO2 were evidenced by a combination of in situ ambient-pressure X-ray Photoelectron Spectroscopy (AP-XPS) and Fourier Transform Infrared Spectroscopy (FTIR) with a transmission cell. AP-XPS showed that the catalysts are composed of a Cu2+, Zr3+, and Zr4+ mixture and two kinds of Zn2+ species. After the H2 reduction process, only Cu2+ was reduced to Cu0. The Zn and Zr species were oxidized by the dissociated O* species. In situ transmission FTIR showed that CO was adsorbed onto the Cu+/0 sites. The catalyst with the higher surfactant molar ratio exhibited the highest CO2 conversion close to the equilibrium conversion, as well as a good methanol formation rate.

Mechanistic insight into the catalytically active phase of CO2 hydrogenation on Cu/ZnO catalyst

The catalytical active phase and reaction mechanism of methanol synthesis by hydrogenation of carbon dioxide on the surface of Cu/ZnO/Al2O3 catalyst become controversial topics in recent years. In this work, density functional theory calculations are employed to explore the possible mechanisms of the CO2 hydrogenation on three possible active phases, namely Zn/Cu interface, ZnO/Cu interface and hydroxylated Zn/Cu surface (i.e., ZnOH/Cu), which may exist in Cu/ZnO/Al2O3 catalyst under realistic conditions. It is more favorable that CO2 activation takes place by the formate pathway rather than the Reverse Water-Gas Shift pathway. Furthermore, the surface hydroxyl group could significantly increase the activity of formate pathway by improving the hydrogenation steps of HCOO to HCOOH and H3CO to H3COH, which are usually deemed as the rate-determining steps. These results suggest that the ZnOH/Cu phase is not only the most stable but also the most active phase for CO2 activation among Zn/Cu, ZnO/Cu and ZnOH/Cu, which could provide more insight into the design of highly efficient catalyst by tuning the surface active phase under operative conditions.

Modern View of the Mechanism of Methanol Synthesis on Cu-Containing Catalysts

Recent publications on the mechanism of methanol synthesis on Cu-containing catalysts were critically analyzed. The following mechanisms can be distinguished based on the key intermediates: formate, carbonate, carboxyl, and formyl. A stepwise mechanism of conversion of CO2 and CO into methanol was proposed taking into account the available experimental and calculated data. According to this mechanism, hydrogenation of CO2 starts with interaction of a CO2 molecule with dissociated hydrogen chemisorbed on the copper surface, forming monodentate formate, which easily transforms into bidentate formate. Subsequent hydrogenation of bidentate formate through a series of intermediates forms methanol. Another possible route of CO2 conversion in the presence of dissociated hydrogen is formation of carboxyl, which is converted into methanol via several intermediates, including formyl. If CO is present in syngas, its role is to remove the OH groups from the surface via the surface carboxyl (*COOH). Then carboxyl can undergo the following transformations: decomposition to СО2 and Н* and hydrogenation via formyl to methanol. The appearance of carbonate intermediates on the copper surface observed by IR spectroscopy at low pressures is not related to the mechanism of methanol synthesis. Some of the results of experiments obtained in the study of transition states require additional studies.

Methanol synthesis from CO2/H2 on Cu (1 0 0): Two-tier ab initio molecular dynamics study

We carried out a two-tier ab initio molecular dynamics approach to investigate the molecular-level mechanism of methanol synthesis from CO2/H2 on a Cu (1 0 0) surface. The first-tier calculations were performed with the surface covered with the maximum number of adsorbates, and the second-tier calculations only with one set of the reactant species. A novel intermediate HCOHOH* was discovered, resulting in two reaction routes to form methanol. The first route is the attack on HCOHOH* by H2 molecule, and the second is a proton transfer reaction between two adjacent HCOHOH*s. This finding confirms the existence of the HCOHOH* intermediate suggested in an experimental study. The proposed two reaction paths have the same largest barrier of 0.68 eV for the rate-limiting step, which agrees with the mean activation energy at 0.77 ± 0.06 eV determined experimentally.

Manos Mavrikakis

ChemCatChemVolume 11, Issue 13 p. 2941-2941 InterviewFree Access Manos Mavrikakis First published: 05 June 2019 https://doi.org/10.1002/cctc.201900802AboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinked InRedditWechat Abstract Professor Mavrikakis was interviewed in celebration of his ACS Gabor Somorjai Award 2019. Manos Mavrikakis Professor Mavrikakis was interviewed in celebration of his ACS Gabor Somorjai Award 2019. Position: Paul A. Elfers Professor of Chemical Engineering, University of Wisconsin-Madison (USA) E-mail: emavrikakis@wisc.edu Homepage: http://directory.engr.wisc.edu/che/Faculty/Mavrikakis_Manos/ ORCID: 0000-0002-5293-5356 Education: Diploma, Chemical Engineering; National Technical University of Athens (1988) MS Chemical Engineering; University of Michigan – Ann Arbor (1989) MS Applied Mathematics; University of Michigan – Ann Arbor (1993) PhD Chemical Engineering & Scientific Computing; University of Michigan – Ann Arbor (1994). Advisors: John L. Gland and Johannes W. Schwank. Postdoc – University of Delaware (1996-97). Advisor: Mark A. Barteau. Marie Curie Postdoctoral Fellow – Technical University of Denmark (1997-1999). Advisor: Jens K. Nørskov. Awards: 2019 ACS Gabor A. Somorjai Award for Creative Research in Catalysis; 2014 AIChE R. H. Wilhelm Award in Chemical Reaction Engineering; 2009 Paul H. Emmett Award in Fundamental Catalysis. Hobbies: Science fiction/biographies; hiking Figure 1Open in figure viewerPowerPoint Manos Mavrikakis The thing I like most about my work is the frequency at which new scientific questions pop up in research. Chemistry/science is fun because you can satisfy your personal curiosity about how nature works. Young people should study chemistry because it has a very wide range of applications affecting quality of life. The secrets of being a successful scientist are to be dedicated and committed to your goals. The most important lesson I have learnt is that hard work is essential to success. What is the secret of running a successful group? Lead by example – scientific integrity and hard work ethics are some of the core values a group leader should instill in their group members. Do you have any tips for fruitful collaborations? Define expectations from the very beginning in terms of deliverables and timeline. Respect the needs of all parties when gathering data and take time to think on how to rationalize them. Always engage in healthy scientific discussions, which should be approached with an open mind. It is okay to play devil's advocate with a constructive attitude. What do you consider the most exciting developments in your field? The development of new powerful materials characterization techniques that allow scientists to discover unexpected atomic-scale information about catalysts, under reaction conditions that are closer than ever to real operating conditions. This information enables the construction of more accurate models which, combined with powerful theoretical methods, allows a deeper understanding of how catalysts work. My 3 top papers: 1“Effect of Strain on the Reactivity of Metal Surfaces”: M. Mavrikakis, B. Hammer, J. K. Nørskov, Phys. Rev. Lett. 1998, 81, 2819. (Strain can be found everywhere and can be used to manipulate the reactivity of catalysts). CrossrefWeb of Science®Google Scholar 2“Alloy Catalysts Designed from First Principles”: J. Greeley, M. Mavrikakis, Nat. Mater. 2004, 3, 810. (Importance of adsorbate-induced segregation in bimetallic catalysts). CrossrefCASPubMedWeb of Science®Google Scholar 3“Mechanism of Methanol Synthesis on Copper through CO and CO2 hydrogenation”: L. C. Grabow, M. Mavrikakis, ACS Catal. 2011, 1, 365. (Methanol synthesis over copper catalysts is one of the most important large-scale industrial processes). CrossrefCASWeb of Science®Google Scholar Volume11, Issue13July 4, 2019Pages 2941-2941 This article also appears in:Catalysis Awards FiguresReferencesRelatedInformation

Role of Surface Species Interactions in Identifying the Reaction Mechanism of Methanol Synthesis from CO2Hydrogenation over Intermetallic PdIn(310) Steps

Considerable attention has been paid to the development of new catalysts for methanol synthesis from CO2 hydrogenation for a long period of time. The PdIn intermetallic catalyst was found recently ...

A DFT Study of Methanol Synthesis from CO2 Hydrogenation on the Pd(111) Surface

During the process of catalytic conversion of CO2 to valuable chemical products, Pd used as catalysts or modifiers shows promising effect on CO2 hydrogenation. The mechanism of methanol synthesis from the hydrogenation of CO2 on the Pd(111) surface was studied using density functional theory calculations in present work. On the Pd(111) surface, CO2 firstly hydrogenates to HCOO or COOH, each of which then reacts with the surface H atom to form HCOOH. Next, HCOOH dissociates to OH and HCO that will be consecutively hydrogenated to H2CO, H3CO and H3COH. CO is the main side product of CO2 hydrogenation on the Pd(111) surface with an activation barrier of 1.09 eV. The hydrogenation of HCO species with the surface H atom to form H2CO plays as the rate determining step for CO2 hydrogenation to methanol with the barrier of 0.91 eV. Our calculated results are favorable for the understanding of the mechanism of CO2 conversion on not only Pd-based catalysts but also Pd modified catalysts. The mechanism of methanol synthesis from the hydrogenation of CO2 on the Pd(111) surface was studied using density functional theory calculations.

Understanding methanol synthesis from CO/H2 feeds over Cu/CeO2 catalysts

Understanding copper-based methanol synthesis catalysts as a function of catalyst type and applied reaction conditions is an area of active industrial and academic research. In this work, results of a methanol synthesis study over a Cu/CeO2 catalyst using CO/H2 feeds are presented, using catalyst performance data combined with catalyst characterisation information (DRIFTS, XPS, TPR, XRD) obtained during start-up and under steady state methanol synthesis conditions. The results indicate that the active site and reaction mechanism for methanol synthesis over Cu/CeO2 are different from the conventional Cu/ZnO/Al2O3 catalyst, with CO, rather than CO2, being the carbon source for methanol. Fixed-bed micro reactors were employed to obtain catalyst performance data in discrete bed sectors using experimental spatial discretisation methods. Methanol synthesis activity over Cu/CeO2 from CO/H2 is preceded by transient CO2 formation, with the onset of methanol synthesis activity observed when the CO2 formation reaches its peak. Considerable differences between reactor bed sectors are observed during start-up, with CO2 formation, CO2 re-adsorption (as surface carbonates and formates), methanol formation and transient methanol decomposition occurring to different degrees and at different time scales.The interfaces of defective CeO2−x in contact with highly dispersed copper particles form the active site of the catalyst under steady-state methanol synthesis conditions, with the copper oxidation state being a combination of 0 and +1 states. The CeO2−x defect sites are formed during start-up upon reaction of CeO2 with CO. The CO2 thus formed leads to catalyst deactivation due to build-up of carbonate and formate species on the catalyst surface. A gradient of progressive poisoning/deactivation is observed going further down the catalyst bed, where the level of deactivation can be controlled by modifying the CO content in the feed. CO2 thus acts as a poison for the Cu/CeO2 catalyst, and addition of even low levels of CO2 to the feed leads to an evenly deactivated catalyst. During start-up in CO/H2, transient CO2 and H2O formation is also observed in the case of Cu/ZnO/Al2O3, ascribed to partial reduction of ZnO, similar to the partial reduction of CeO2 as seen in Cu/CeO2. The key difference between the two systems is the absence of CO2 and H2O re-adsorption on Cu/ZnO/Al2O3, resulting in stable methanol production distributed equally over the catalyst bed. Introduction of CO2 to the CO/H2 feed in case of Cu/ZnO/Al2O3 leads to reduction of Cu+ to Cu0 and a change in methanol synthesis mechanism from CO to CO2 hydrogenation.

Theoretical study of methanol synthesis from CO2 and CO hydrogenation on the surface of ZrO2 supported In2O3 catalyst

The interactions between ZrO2 support and In2O3 catalyst play pivotal role in the catalytic conversion of CO2 to methanol. Herein, a density functional theory study has been conducted to research the mechanism of methanol synthesis from CO2 and CO hydrogenation on the defective ZrO2 supported In2O3(110) surface (D surface). The calculations reveal that methanol is produced mainly via the HCOO reaction pathway from CO2 hydrogenation on D surface, and the hydrogenation of HCOO to form H2COO species with an activation barrier of 1.21 eV plays the rate determining step for the HCOO reaction pathway. The direct dissociation of CO2 to CO on D surface is kinetically and energetically prohibited. Methanol synthesis from CO hydrogenation on D surface is much facile comparing with the elementary steps involved in CO2 hydrogenation. The rate determining step of CO hydrogenation to methanol is the formation of H3CO species on the vacancy site with a barrier of 0.51 eV. ZrO2 support has significant effect on the suppressing of the dissociation of CO2 and stabilization of H2COO species on the surface of In2O3 catalyst.

Reaction mechanisms of methanol synthesis from CO/CO2 hydrogenation on Cu2O(111): Comparison with Cu(111)

A systematic theoretical study was performed to investigate methanol synthesis from CO/CO2 hydrogenation and the water-gas-shift (WGS) reaction on Cu(111) and Cu2O(111) surfaces using density functional theory (DFT) and kinetic Monte Carlo (KMC) simulations. Specifically, DFT was used to investigate methanol synthesis from CO/CO2 hydrogenation on these surfaces at P=80atm, T=553K and (CO+ CO2)/H2=20/80. The results show that methanol can be synthesized from CO or CO2 hydrogenation and is dependent on the catalyst’s preparation as well as the active site type. Further, CO is the main carbon source when the surface is predominantly covered by Cu+ species. However, CO2 is the primary carbon source when metallic Cu covers the surface. Under the reaction conditions investigated, H2 and CO easily reduce Cu2O to metallic Cu, and the Cu+ species are stabilized by the presence of H2O, CO2, carrier (such as MgO) or alkali metals. For this reason, the scale of methanol produced from CO or CO2 hydrogenation depends on the ratio of Cu+/Cu0.

Hydrogenation of CO2to Methanol at Atmospheric Pressure over Cu/ZnO Catalysts: Influence of the Calcination, Reduction, and Metal Loading

Cu/ZnO catalysts have been widely studied for the hydrogenation of carbon dioxide to methanol at atmospheric pressure. In the work described here, several interesting issues are highlighted that have rarely been considered previously. An extensive study of the influence of the calcination and reduction temperatures and the metal loading was carried out. The best conditions found for catalyst preparation were calcination at 350 °C and reduction at 200 °C. The role of the different oxidation states of copper (Cu2+, Cu1+, and Cu0) was proven in the methane and methanol formation. CuZn alloy formation was observed when a reduction temperature of 400 °C was used. The use of this alloy led to higher methanol selectivity at higher temperatures (>200 °C). Finally, the metal loading study confirm the dual-site nature of the methanol synthesis mechanism.