High Temperature Water Gas Shift Research Articles

Investigating the effects of synthesis parameter on textural and catalytic properties of ZnO-CuO-Al2O3-Cr2O3 mixed oxide in water gas shift reaction

The present study has investigated the influence of preparing conditions, including aging temperature and time, pH, and Tcalcination, on the co-precipitated ZnO-CuO-Al2O3-Cr2O3 mixed oxide at a high-temperature water gas shift reaction. XRD, BET, FTIR, TG-DTA, SEM, TEM, and H2-TPR were used to characterize the relationships between the synthesis parameters and the physicochemical features. The investigation proved that the activity in aging 5 h could be related to higher pore volume and lower crystalline size of 0.24 cm3g-1 and 6.4nm, respectively. Also found that increasing the aging temperature to 60°C results in a rise in the surface area and particle size of less than 6nm, enhancing the catalyst activity. The findings showed that raising the Tcalcination reduced the surface area from 132 to 65m2 g-1. It has been concluded that the CO conversion of 70% was obtained at a pH of 10 when aged at 60°C for 5 hours and calcination temperature of 400°C.

Volcano-Shaped Correlation Dictated Superior Activity for Ultralow Al-Doped Iron Oxide toward High-Temperature Water–Gas Shift Reaction

Volcano-Shaped Correlation Dictated Superior Activity for Ultralow Al-Doped Iron Oxide toward High-Temperature Water–Gas Shift Reaction

Modeling analysis of water-gas-shift reaction on catalyst-packed ceramic-carbonate dual-phase membrane reactor for hydrogen production

Water-gas shift (WGS) reaction for hydrogen production and CO2 removal/capture in a catalyst-packed CO2-permselective membrane reactor is studied experimentally and simulated with a computational model. The reactor utilizes a tubular dense ceramic-carbonate dual-phase membrane with a commercial high-temperature WGS catalyst. Equations governing CO2 permeation through the membrane and WGS reaction kinetics on the catalyst were obtained through independent CO2 permeation experiments and a fixed-bed reaction kinetic study. The simulation results using the validated model are presented to examine the effects of feed gas composition, steam/CO ratio, gas hourly space velocity, temperature, reactor pressure, sweep to feed molar flow rate ratio, and the membrane area to catalyst volume ratio on the performance of the membrane reactor for WGS with CO2 removal. Under optimized conditions, the catalyst-packed membrane reactor for WGS demonstrates significantly enhanced CO conversion and product H2 purity by effectively removing/capturing CO2 from the WGS reaction side.

Enhanced activity of bimetallic Fe-Cu catalysts supported on ceria toward water gas shift reaction: synergistic effect

Within the “hydrogen chain”, the hight-emperature water gas shift reaction represents a key step to improve the H2 yield and adjust the H2/COx ratio to fit the constraints of downstream processes. Despite the commercial application of the high-temperature water gas shift, novel catalysts characterized by higher intrinsic activity (especially at low temperatures), good thermal stability, and no chromium content are needed. In this work, we propose bimetallic iron-copper catalysts supported on ceria, characterized by low active phase content (iron oxide + copper oxide < 5 wt %). Fresh and used samples were characterized by inductively coupled plasma mass spectrometry, X-ray diffraction, nitrogen physisorption, scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy, and temperature programmed reduction in hydrogen to relate physicochemical features and catalytic activity. The sample with iron/copper ≈ 1 and 4 wt % active phase content showed the best catalytic properties in terms of turnover frequency, no methane formation, and stability. Its unique properties were due to both strong iron-copper interaction and strong metal-support interaction, leading to outstanding redox behavior.

An investigation of water gas shift reaction in a Pd-alloy membrane reactor with an optimized crossflow configuration

In this study, the performance of a high-temperature water gas shift reaction (WGSR) using a Fe-Cr catalyst along with a Pd alloy membrane was simulated by computational fluid dynamics (CFD). The influences of using Pd membranes, catalytic layer thickness ratio (R/R0), Reynolds number, and steam-to-CO ratio (S/C) on the reaction were investigated by comparing CO conversion and hydrogen recovery (HR). In the CFD simulation, one-tube and four-tube systems were simulated at 500 °C. This study also compared the performance between tandem and optimized configurations. The results show that the CO conversion can be improved up to 22.9% when the WGSR reactor system uses a Pd membrane compared to the system without a Pd membrane. The system has the best hydrogen recovery performance at S/C = 4 and R/R0 larger than 1.5. At Re=5, the optimized configuration for CO conversion has better performance when R/R0 is larger than 1.75. Compared to the tandem configuration, the optimized configuration also shows better performance for HR at every R/R0. The results indicate that a Pd membrane and optimized configuration can significantly improve CO conversion and that R/R0 and S/C optimization is very important for effective reactor performance.

Design of Cr-Free Promoted Copper-Iron Oxide-Based High-Temperature Water-Gas Shift Catalysts.

The effect of Ce addition to the Cr-free Al-promoted Cu-Fe oxide-based catalysts is investigated. Catalyst characterization (X-ray diffraction (XRD), in situ Raman spectroscopy, high-sensitivity low-energy ion scattering (HS-LEIS), Brunauer-Emmett-Teller (BET) analysis), CO-temperature-programmed reduction chemical probing, and steady-state WGS activity reveal that (i) in the absence of Al, Ce addition via coprecipitation has a detrimental effect on the catalytic activity related to the poor thermostability and formation of less active Ce-Cu-O NPs, (ii) the addition of Ce via coprecipitation also does not improve the performance of the CuAlFe catalyst because of the formation of a thick CeOx overlayer on the active Cu-FeOx interface, and (iii) impregnation of Ce onto the CuAlFe catalyst exhibits significant improvement in catalytic performance due to the formation of a highly active CeOx-FeOx-Cu interfacial area. In summary, Al does not surface-segregate and serves as a structural promoter, while Ce and Cu surface-segregate and act as functional promoters in Ce/CuAlFe mixed oxide catalysts.

Hydrogen production from waste-derived synthesis gas over Ni(x)Fe(3-x)-CeO2 catalyst: optimization of Ni/Fe ratio

In this study, the effect of the Ni/Fe molar ratio on the Ni(x)Fe(3-x)-CeO2 catalyst was investigated for the high-temperature water-gas shift reaction, which produces hydrogen from waste-derived synthesis gas. The catalysts were synthesized via a co-precipitation method, using different Ni/Fe molar ratios (0.5:2.5, 1.0:2.0, 1.5:1.5, 2.0:1.0, and 2.5:0.5). The physicochemical properties of these catalysts were analyzed by Brunauer–Emmett–Teller (BET), X-ray diffraction (XRD), temperature-programmed reduction using hydrogen (H2-TPR), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and H2-O2 pulse analyses to determine their reaction performance. The Ni1.0Fe2.0-CeO2 catalyst exhibited the highest activity (Xco = 88%, T = 500 °C) without any side reactions at a high gas hourly space velocity of 41,823 mL·g−1 h−1, compared to the other catalysts tested, owing to its high oxygen vacancies and oxygen storage capacity (OSC). In addition, when the Ni/Fe molar ratio was higher than 1, a side reaction (methanation) occurred. Therefore, it was concluded that the Ni1.0Fe2.0-CeO2 catalyst is optimal for hydrogen production via the high-temperature water-gas shift reaction from waste-derived synthesis gas.

Increasing carbon efficiency for DME production from wheat straw and renewable electricity – Analysis of 14 system layouts

Liquid fuels like dimethyl-ether (DME), produced from biomass and electricity are crucial for decarbonizing the shipping industry. In this work, the production of DME from wheat straw through gasification is presented. It was shown how the process can be optimized by using 1) two-stage instead of one-stage DME synthesis, 2) partial oxidation of the produced gas and 3) a hydrogen quench for high-temperature reverse water gas shift reactions. The investigation was conducted by stepwise introducing the different process steps, leading to investigating 14 different plant layouts. This enabled a systematic analysis of the influence of different process steps by looking at the changes in carbon efficiency and energy efficiency. In all plants, DME and bio-ash, which acts as a soil amendment and carbon sink, were produced. 10 of the 14 plants additionally produced high-quality bio-oil. The analysis showed that all the introduced measures increased the carbon efficiency of the plants. At the same time, they increased the net electricity consumption. The highest energy efficiency reached was 57.5 %. A different plant reached the highest carbon efficiency with 84.0 %.,while having the highest net electricity consumption (45.2 MW at a biomass input of 50 MW (LHV)).

Conceptual design of a process for hydrogen production from waste biomass and its storage in form of liquid ammonia

In this work we present the simulation of a plant for the exploitation of renewable hydrogen (e.g. from biomass gasification) with production of renewable ammonia as hydrogen vector and energy storage medium. The simulation and sizing of all unit operations were performed with Aspen Plus® as software. Vegetable waste biomass is used as raw material for hydrogen production, more specifically pine sawdust.The hydrogen production process is based on a gasification reactor operating at high temperature (700–800 °C), in the presence of a gasifying agent such as air or steam. At the outlet, a solid residue (ash) and a certain amount of gas, which mainly contains H2, CH4, CO and some impurities (e.g. sulphur or chlorine compounds) are obtained. Subsequently this gas stream is purified and treated in a series of reactors in order to maximize the hydrogen yield. In fact, after the removal of the sulphur compounds through an absorption column with MEA (to avoid poisoning of the catalytic processes), 3 reactors are arranged in series: Methane Steam Reforming (MSR), High temperature Water-Gas Shift (HT-WGS), Low temperature Water-Gas Shift (LT-WGS).In the first MSR reactor, methane reacts at 1000 °C in presence of steam and a nickel-based catalyst, in order to obtain mainly H2, CO and CO2. Subsequently two steps of WGS are present to convert most of the CO into H2 and CO2. Also these reactions are carried out in the presence of a catalyst and with an excess of water.All the oxygenated compounds must be carefully eliminated: the remaining traces of CO are methanated while CO2 is removed by a basic scrubbing with MEA (35 wt%) inside an absorption column. The Haber-Bosch synthesis of ammonia was carried out at 200 bar and in a temperature range between 300 and 400 °C, using two catalysts: Fe (wustite) and Ru/C.As overall balance, from an hourly flow rate of 1000 kg of dry biomass and 600 kg of nitrogen, 550 kg of NH3 at 98.8 wt% were obtained, demonstrating the proof of concept of this newly designed process for the production of hydrogen from renewable waste biomass and its transformation into a liquid hydrogen vector to be easily transported and stored.

Effect of Stoichiometry and Method of Synthesis of Powdered Cu–Fe–Al Precursors on the Stability and Activity of CuFeAlO/CuFeAl Ceramometals in the High-Temperature Water Gas Shift Reaction

Effect of Stoichiometry and Method of Synthesis of Powdered Cu–Fe–Al Precursors on the Stability and Activity of CuFeAlO/CuFeAl Ceramometals in the High-Temperature Water Gas Shift Reaction

Facile synthesis of M-CuFe2O4 (M= Al2O3, CeO2, La2O3, ZrO2, Mn2O3) catalysts using a one-pot method and their applications in high-temperature water gas shift reaction

Water gas shift reaction is an essential process of hydrogen production and carbon monoxide removal from syngas. In this study, the promotional effect of ZrO2, CeO2, La2O3, Al2O3, and Mn2O3 was investigated on the CO conversion and thermal stability of the copper ferrite in high-temperature water gas shift reaction (HTSR) and hydrogen purification. The powders were synthesized by a simple solid-state route and characterized by XRD, H2-TPR, SEM, FT-IR, TG-DTA, and BET analyses. Promoters (ZrO2, CeO2, La2O3, Al2O3, and Mn2O3) could affect the WGSR performance in activity and stability. In the M-CuFe2O4 catalyst, alumina acts as a texture promoter and aids in the fine dispersion of copper ferrite. The results indicated that the surface area of the Al2O3–CuFe2O4 (210 m2/g) catalyst was higher than the other samples. This catalyst presented higher CO conversion in HTSR and had higher stability at 1000 min on stream. It was found that the incorporation of different contents of alumina had a significant influence on the textural and catalytic properties of the CuFe2O4-based catalysts. The 30%Al2O3–70%CuFe2O4 catalyst exhibited the highest CO conversion of 65% at 350 °C, uniform pore size distribution, and intense interaction between copper ferrite and alumina, causing the effective stabilization of the active phase in the catalyst structure. The findings of this study represent that the solid-state method, due to its simplicity and creation of a mesoporous structure, can also be applied for the preparation of many heterogeneous metal oxide catalysts.

Enhanced Fe–Cr dispersion on mesoporous silica support using surfactant-assisted melt-infiltration for the water-gas shift reaction in waste-to-hydrogen processes

Iron-chromium/SBA-15 (Fe–Cr/SBA-15) catalysts for high-temperature water-gas shift reactions (HTS) were prepared using the surfactant-assisted melt-infiltration (SAMI) method. The SAMI method was used to synthesize an efficient catalyst that could simultaneously achieve high dispersion and loading (Fe: 40 wt% and Cr/Fe molar ratio: 0.25) without a liquid solution. According to X-ray diffraction (XRD) and transmission electron microscopy analyses, it was observed that the Span60 surfactant enhanced Fe3O4 particle dispersion. N2 adsorption-desorption analysis indicated that the Fe3O4 and chromium oxide particles were thoroughly infiltrated inside the mesopores of the SBA-15 support. XRD and temperature-programmed-reduction analyses revealed that the well-dispersed Fe3O4 acted as active sites for the HTS reaction when Span60 was added to the Fe–Cr catalyst. In other words, the Fe–Cr catalyst synthesized via SAMI exhibited better performance and stability for the HTS reaction than that prepared without the surfactant.

Substituting Chromium in Iron-Based Catalysts for the High-Temperature Water-Gas Shift Reaction.

A set of doped iron oxides (chromium, aluminum, gallium, indium, manganese, zinc, niobium) were prepared by a one-step coprecipitation/calcination approach evaluated for their WGS activity under industrially relevant conditions and characterized in detail. The WGS activity after ageing the doped catalyst for 4 days at 25 bar follows the order chromium ≈ aluminum > gallium > indium > manganese > zinc > niobium for copper-codoped catalysts. The activated catalysts predominantly consist of magnetite, irrespective of the dopant. Mössbauer spectra of aged catalysts showed that aluminum and zinc occupy both tetrahedral and octahedral sites of magnetite, while chromium, gallium, indium, manganese, and niobium preferentially substitute octahedral iron. The incorporation of trivalent metal ions of similar size to octahedral Fe3+ (i.e., chromium, aluminum, gallium) results in moderate to high CO conversion, irrespective of incorporation in tetrahedral or octahedral sites. The substitution of Fe2+ with Mn2+ results in an increased Fe3+/Fe2+ ratio. Incorporation of Zn2+ in tetrahedral sites (replacing Fe3+ ions) leads to a complex structure where the charge balance is compensated from the octahedral sites. Separate dopant metal oxide phases were observed in indium- and niobium-doped catalysts. XPS shows that copper is present as a separate phase in activated copper-codoped catalysts. Aluminum is identified as the most promising promoter for substituting chromium in commercial high-temperature WGS catalysts on the basis of their similar high CO conversion although incorporation of these dopants into the magnetite structure differed substantially.

Water-gas shift reaction in ceramic-carbonate dual-phase membrane reactor at high temperatures and pressures

Water-gas-shift (WGS) reaction is a critical step in integrated gasification combined cycles (IGCC) power plants with CO2 capture. Membrane reactors made with a CO2-permselective ceramic-carbonate dual-phase (CCDP) membrane offers the potential to enhance hydrogen yield with simultaneous CO2 capture for WGS reaction. The present work studies operation of WGS reaction in a tubular membrane reactor made of samarium-doped ceria infiltrated with lithium/sodium molten carbonate mixture. The WGS reaction was performed in the membrane reactor with and without a high-temperature WGS catalyst at 800–850 °C, feed pressure of 7 bar, the space velocity of 150–3000 h−1, and a feed gas mixture of 45.7/13.1/41.3 mol% CO/CO2/N2 with steam to carbon ratio of 4. The results show that the catalyst-free membrane reactor can convert 92% of carbon monoxide into CO2 and H2 and recover 29% CO2 at 850 °C and a space velocity of 150 h−1. However, in the catalyst-free membrane reactor, a significant amount of unwanted carbon deposition is observed. The side reactions can be minimized by reducing the operating pressure and increasing the operating temperature and space velocity, and completely avoided using a high-temperature catalyst at space velocity>500 h−1. The membrane reactor with a WGS catalyst achieves CO conversion of about 85%, above the equilibrium conversion, and 40% CO2 recovery without carbon deposition at high temperature and pressure. The membrane remains in the same structure and gas-tightness after the WGS reaction tests.

Alkali promoted zinc-aluminum oxide as high temperature water gas shift catalyst

A new kind of high-temperature water gas shift catalyst based on K-promoted ZnO/ZnAl2O4, introduced by Haldor Topsøe as SK-501 Flex™, has begun to replace the well-known Fe/Cr oxide catalysts in the industry. In this research article, we focus on optimization of the catalyst system, especially on promotion with alkali metals and on structural characterization using X-ray diffraction. The promotional effect of the alkali metals increases in the order Li < < Na < < Cs < Rb < K. With K, a 20-fold increase of the mass-based intrinsic rate constant compared to an un-promoted sample is observed. The optimum in the K-content, 2.1 wt%, corresponds to a surface concentration of 0.0057 mmol/m2 or 0.0059 mmol/m2 if K only decorates the ZnAl2O4 spinel surface. This coverage coincides with the surface concentration of Al vacancies on the dominating spinel (111) facet, the so-called kagome layer, with a coverage of 0.00586 mmol/m2. Potassium decoration of the spinel surface is corroborated by FTIR studies of promoted and un-promoted samples in a CO atmosphere. The promotion by potassium is both structural, inhibiting growth of the spinel crystals as evidenced by XRD and BET surface area measurements, but also electronic since the activity per surface area strongly increases on K-promotion. Finally, our studies include long term tests of thermal stability and tolerance towards H2S.

Development of Co–Nb–CeO2 Catalyst for Hydrogen Production from Waste-Derived Synthesis Gas Using Techno-Economic and Environmental Assessment

A comparative study to obtain a cost-competitive catalyst was performed to produce hydrogen via the high temperature water gas shift (WGS) reaction using synthesis gas (syngas) derived from waste. First, several selected active metals on Nb–CeO2 support and preparation methods were applied to prepare highly active and stable catalysts under severe reaction conditions. Various characterization methods were employed to understand the correlation between catalytic activity and physicochemical properties of the prepared catalysts. Among the Me–Nb–CeO2 (Me = Co, Cu, Fe, and Zn) catalysts, Co–Nb–CeO2 showed the highest activity at a high gas hourly space velocity of 315,282 mL·g–1·h–1 (temperature = 500 °C, XCO ≈ 84%). This was attributed to the high Brunauer–Emmett–Teller surface area and oxygen storage capacity of the Co–Nb–CeO2 catalyst. In addition, to investigate the effect of preparation method, various methods, including coprecipitation, incipient wetness impregnation, sol–gel, and hydrothermal methods, were applied for the synthesis of the Co–Nb–CeO2 catalyst. The Co–Nb–CeO2 catalyst prepared using the coprecipitation method exhibited high activity without significant deactivation for 60 h. This was attributed to the high oxygen storage capacity and intimate interaction between Co and the Nb–CeO2 support. Finally, techno-economic analysis and environmental impact assessment were performed for the Co–Nb–CeO2 catalysts, prepared by different preparation methods to identify the most promising catalyst for the production of hydrogen using the syngas derived from waste. By comparison with a commercial catalyst, it was shown that Co–Nb–CeO2 synthesized using coprecipitation is a promising, cost-effective, and eco-friendly catalyst with high activity.

Waste to worth: A high-temperature water-gas shift magnetite catalyst with encapsulated core-shell structure from coal fly ash

In this paper, we demonstrate the synthesis of magnetite-based, encapsulated catalyst with a core-shell structure from coal fly ash, an industrial solid waste, and its application to industrially important high temperature water-gas shift reaction (HT-WGSR). The catalyst precursor was first synthesized through a leaching-precipitation-hydrothermal process, leading to the formation of a nanosheet-like hematite precursor consisting of Fe3+ as primary element and minor cations including Al3+, Mg2+ and other cations (e.g. Ca2+ and Ti4+). During the WGSR, the nanosheets broke into smaller particles with a core of magnetite with a diameter of ~20 nm, whereas the inherent impurity elements were activated and migrated to the outer surface forming a shell with a thickness of ~4 nm. Due to the protection of shell, the as-synthesized catalyst exhibited improved activity, thermal stability and long-term durability for HT-WGSR at 400 °C and 450 °C. Compared to the pure hematite, this catalyst exhibited much higher activity and stability, i.e., increased CO conversion and decreased deactivation rate constant, by a factor of four and three, respectively. Additionally, through a bottom-up reverse synthesis, we have confirmed that Al3+ functioned as a textual promoter enhancing the interfacial area of the catalyst. On the other hand, the presence of minor impurity elements, in particular 2.58 wt% Mg2+ and 0.18 wt% Ti4+, were found to increase the basicity, and promote the adsorption rate of CO, the redox of catalysts, and the alteration of the reaction mechanism from regenerative to associative with the formation of a strong intermediate formate. This study not only opens a new direction on the valorization of solid waste into high-value catalysts, promoting the sustainability of solid waste management, but also provides an alternative, cost-effective and scalable approach for the design and fine-tuning of encapsulated catalysts.

Effect of ZrO2 on the performance of Co–CeO2 catalysts for hydrogen production from waste-derived synthesis gas using high-temperature water gas shift reaction

In this study, highly active and stable CeO 2 , ZrO 2 , and Zr (1- x ) Ce ( x ) O 2 -supported Co catalysts were prepared using the co-precipitation method for the high-temperature water gas shift reaction to produce hydrogen from waste-derived synthesis gas. The physicochemical properties of the catalysts were investigated by carrying out Brunauer-Emmet-Teller, X-ray diffraction, CO-chemisorption, Raman spectroscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and H 2 -temperature-programmed reduction measurements. With an increase in the ZrO 2 content, the surface area and reducibility of the catalysts increased, while the interaction between Co and the support and the dispersion of Co deteriorated. The Co–Zr 0.4 Ce 0·6 O 2 and Co–Zr 0.6 Ce 0·4 O 2 catalysts showed higher oxygen storage capacity than that of the others because of the distortion of the CeO 2 structure due to the substitution of Ce 4+ by Zr 4+ . The Co–Zr 0.6 Ce 0·4 O 2 catalyst with high reducibility and oxygen storage capacity exhibited the best catalytic performance and stability among all the catalysts investigated in this study. • CeO 2 , ZrO 2 , and Zr (1-x) Ce (x) O 2 -supported Co catalysts were prepared. • WGS reaction was carried out over the catalysts to produce hydrogen from syngas. • Oxygen storage capacity and reducibility were dependent on the ratio of Ce/Zr. • Co–Zr 0.4 Ce 0·6 O 2 showed the best performance among the prepared catalysts. • This performance was relating to its high oxygen storage capacity and reducibility.

Promotion of methanation suppression by alkali and alkaline earth metals in Ni-CeO2 catalysts for water–gas shift reaction using waste-derived synthesis gas

In this study, alkali and alkaline earth metal-promoted Ni-CeO2 catalysts were developed for the high-temperature water–gas shift reaction of waste-derived synthesis gas in which hydrogen is produced. The elements K, Ca, Mg, and Ba were selected to repress methanation, which is a major side reaction of Ni-based catalysts. The prepared catalysts were characterized using different techniques including the Brunauer–Emmett–Teller method, X-ray diffraction, H2-temperature programmed reduction, CO2-temperature programmed desorption, H2-chemisorption, and X-ray photoelectron spectroscopy to determine the correlations between the catalyst activity and their properties. The results show that the alkali and alkaline earth metal-promoted Ni-CeO2 catalyst effectively suppressed methanation. Among the promoted catalysts, the Ca/Ni-CeO2 catalyst exhibited the highest activity and stability for 18 h at a very high gas hourly space velocity of 1,050,957 h−1, which is mainly due to the high oxygen storage capacity.

Partially sintered copper\u2012ceria as excellent catalyst for the high-temperature reverse water gas shift reaction

For high-temperature catalytic reaction, it is of significant importance and challenge to construct stable active sites in catalysts. Herein, we report the construction of sufficient and stable copper clusters in the copper‒ceria catalyst with high Cu loading (15 wt.%) for the high-temperature reverse water gas shift (RWGS) reaction. Under very harsh working conditions, the ceria nanorods suffered a partial sintering, on which the 2D and 3D copper clusters were formed. This partially sintered catalyst exhibits unmatched activity and excellent durability at high temperature. The interaction between the copper and ceria ensures the copper clusters stably anchored on the surface of ceria. Abundant in situ generated and consumed surface oxygen vacancies form synergistic effect with adjacent copper clusters to promote the reaction process. This work investigates the structure-function relation of the catalyst with sintered and inhomogeneous structure and explores the potential application of the sintered catalyst in C1 chemistry.