High CO₂ conversion via plasma assisted reverse water-gas shift reaction over Ag/ZnO catalyst

Abstract

Reverse water-gas shift reaction represents a strategic pathway for CO₂ utilization. Despite its potential, reverse water-gas shift reaction via conventional thermal-catalysis faces several challenges, including low equilibrium conversion rates due to thermodynamic constraints, high energy consumption, and insufficient product selectivity. Here, this study demonstrates an evident synergetic effect between plasma and Ag/ZnO, on enhancing reverse water-gas shift reaction. The plasma catalytic system achieved significantly improved performance with a remarkable CO₂ conversion rate of 76.5%, a high CO selectivity of 96.8%, and a CO yield of 74.1%, along with an energy efficiency as high as 0.19 mmol·kJ^–1, surpassing the plasma alone system and ZnO catalytic systems. Results from X-ray photoelectron spectroscopy and Auger electron spectroscopy confirm the presence of electronic metal-support interactions between Ag and ZnO, which facilitates the formation of electron-deficient Ag sites and partially reduced ZnO_x species. These reactive sites, along with oxygen vacancies created during reduction treatment, enhance the adsorption and activation of H₂ and CO₂, offering a dominant plasma-assisted surface reaction pathway for the improved reverse water-gas shift reaction. These findings underscore the crucial role of electronic metal-support interactions in manipulating surface environments to facilitate efficient plasma-assisted catalytic reactions, with significant implications for the rational design of catalysts capable of converting CO₂ efficiently under mild conditions.

Graphical abstract

Keywords

non-thermal plasma catalysis / CO₂ conversion / reverse water-gas shift reaction / Ag/ZnO / electronic metal-support interactions

References

[1] Ashford B , Poh CK , Ostrikov K , Chen L , Tu X . Plasma-catalytic CO₂ hydrogenation to ethane in a dielectric barrier discharge reactor. Journal of CO₂ Utilization, 2022, 57: 101882

[2] Chen H , Mu Y , Shao Y , Sarayute C , Huan X , Jiao Y , Hardacre C , Fan X . Nonthermal plasma (NTP) activated metal-organic frameworks (MOFs) catalyst for catalytic CO₂ hydrogenation. AIChE Journal, 2020, 66(4): e16853

[3] Zeng Y X , Wang L , Wu C F , Wang J Q , Shen B X , Tu X . Low temperature reforming of biogas over K-, Mg-, and Ce-promoted Ni/Al₂O₃ catalysts for the production of hydrogen rich syngas: understanding the plasma-catalytic synergy. Applied Catalysis B: Environmental, 2018, 224: 469–478

[4] Zhao T , Hui Y , Li Z . Review of plasma-assisted reactions and potential applications for modification of metal-organic frameworks. Frontiers of Chemical Science and Engineering, 2019, 13(3): 444–457

[5] Ashford B , Wang Y , Poh C K , Chen L , Tu X . Plasma-catalytic conversion of CO₂ to CO over binary metal oxide catalysts at low temperatures. Applied Catalysis B: Environment and Energy, 2020, 276(0): 119110

[6] Li X , Sen Y , Zhang X . A review on the low temperature water-gas-shift reaction: reaction mechanism, catalyst design, and novel process development. Frontiers of Chemical Science and Engineering, 2025, 19(6): 46

[7] Liu M , Yi Y , Wang L , Guo H , Bogaerts A . Hydrogenation of carbon dioxide to value-added chemicals by heterogeneous catalysis and plasma catalysis. Catalysts, 2019, 9(3): 275

[8] Kim Y , Kim K J , Song Y , Lee Y L , Roh H S , Na K . Highly CO-selective Ni-MgO-Ce_xZr_1–xO₂ catalyst for efficient low-temperature reverse water-gas shift reaction. Journal of Industrial and Engineering Chemistry, 2023, 118: 341–350

[9] Ussiri D A N , Lal R . Long-term tillage effects on soil carbon storage and carbon dioxide emissions in continuous corn cropping system from an alfisol in Ohio. Soil & Tillage Research, 2009, 104(1): 39–47

[10] Zhu X , Liu J H , Li X S , Liu J L , Qu X , Zhu A M . Enhanced effect of plasma on catalytic reduction of CO₂ to CO with hydrogen over Au/CeO₂ at low temperature. Journal of Energy Chemistry, 2017, 26(3): 488–493

[11] Liu L , Zhang Z , Das S , Xi S , Kawi S . LaNiO₃ as a precursor of Ni/La₂O₃ for reverse water-gas shift in DBD plasma: effect of calcination temperature. Energy Conversion and Management, 2020, 206: 112475

[12] Chen H , Mu Y , Shao Y , Sarayute C S , Goodarzi F , Mielby J J , Mao B , Sooknoi T , Hardacre C , Kegnæs S . . Effect of metal dispersion and support structure of Ni/silicalite-1 catalysts on non-thermal plasma (NTP) activated CO₂ hydrogenation. Applied Catalysis B: Environmental, 2020, 272: 119013

[13] Chen Y , Chen S , Shao Y , Cui Q , Gao N , Fan X , Chen H . Siliceous mesocellular foam supported Cu catalysts for promoting non-thermal plasma activated CO₂ hydrogenation toward methanol synthesis. Frontiers of Chemical Science and Engineering, 2024, 18(7): 77

[14] Wang L , Yi Y , Wu C , Guo H , Tu X . One-step reforming of CO₂ and CH₄ into high-value liquid chemicals and fuels at room temperature by plasma-driven catalysis. Angewandte Chemie International Edition, 2017, 56(44): 13679–13683

[15] Pastor-Pérez L , Shah M , Le Saché E , Ramirez Reina T . Improving Fe/Al₂O₃ catalysts for the reverse water-gas shift reaction: on the effect of Cs as activity/selectivity promote. Catalysts, 2018, 8(12): 608

[16] Xu S , Sarayute C , Shao Y , Xu S , Wang Y C , Haigh S , Mu Y , Jiao Y , Stere C E , Chen H . . Mechanistic study of non-thermal plasma assisted CO₂ hydrogenation over Ru supported on MgAl layered double hydroxide. Applied Catalysis B: Environmental, 2020, 268: 118752

[17] Liu L , Dai J , Yang Z , Li Y , Su X , Zhang Z . Plasma-catalytic carbon dioxide conversion by reverse water-gas shift over La_0.9Ce_0.1B_0.5B′_0.5O_3–δ perovskite-derived bimetallic catalysts. Chemical Engineering Journal, 2022, 431: 134009

[18] Sun Y , Wu J , Wang Y , Li J , Wang N , Harding J , Mo S , Chen L , Chen P , Fu M . . Plasma-catalytic CO₂ hydrogenation over a Pd/ZnO catalyst: in situ probing of gas-phase and surface reactions. JACS Au, 2022, 2(8): 1800–1810

[19] Tang C W , Chuang S S C . The effect of reduction of pretreated NiO-ZnO catalysts on the water-gas shift reaction for hydrogen production as studied by in situ DRIFTS/MS. International Journal of Hydrogen Energy, 2014, 39(2): 788–797

[20] Ahmad S , Hussain A , Mian S A , Rahman G , Ali S , Jang J . Sensing and conversion of carbon dioxide to methanol using Ag-decorated zinc oxide nanocatalyst. Materials Advances, 2024, 5(3): 1119–1129

[21] WenCYinADaiW L. Recent advances in silver-based heterogeneous catalysts for green chemistry processes. Applied Catalysis: Environment and Energy, 2014, 160–161: 730−741

[22] Mori K , Sano T , Kobayashi H , Yamashita H . Surface engineering of a supported PdAg catalyst for hydrogenation of CO₂ to formic acid: elucidating the active Pd atoms in alloy nanoparticles. Journal of the American Chemical Society, 2018, 140(28): 8902–8909

[23] Brugnoli L , Pedone A , Menziani M C , Adamo C , Labat F . H₂ dissociation and water evolution on silver-decorated CeO₂(111): a hybrid density functional theory investigation. Journal of Physical Chemistry C, 2019, 123(42): 25668–25679

[24] Mohammad A B , Yudanov I V , Lim K H , Neyman K M , Rösch N . Hydrogen activation on silver: a computational study on surface and subsurface oxygen species. Journal of Physical Chemistry C, 2008, 112(5): 1628–1635

[25] Sun K , Zhang Z , Shen C , Rui N , Liu C J . The feasibility study of the indium oxide supported silver catalyst for selective hydrogenation of CO₂ to methanol. Green Energy & Environment, 2022, 7(4): 807–817

[26] Yi Y , Li S , Cui Z , Hao Y , Zhang Y , Wang L , Liu P , Tu X , Xu X , Guo H . . Selective oxidation of CH₄ to CH₃OH through plasma catalysis: insights from catalyst characterization and chemical kinetics modelling. Applied Catalysis B: Environmental, 2021, 296: 120384

[27] Hu J , Kim E M , Janik M J , Alexopoulos K . Hydrogen activation and spillover on anatase TiO₂-supported Ag single-atom catalysts. Journal of Physical Chemistry C, 2022, 126(17): 7482–7491

[28] Wang B , Zhang Q , He J , Huang F , Li C , Wang M . Co-catalyst-free large ZnO single crystal for high-efficiency piezocatalytic hydrogen evolution from pure water. Journal of Energy Chemistry, 2022, 65: 304–311

[29] Silva R L , Franco J A . Raman spectroscopy study of structural disorder degree of ZnO ceramics. Materials Science in Semiconductor Processing, 2020, 119: 105227

[30] Wang D X , Summers C J , Wang Z L . Mesoporous single-crystal ZnO nanowires epitaxially sheathed with Zn₂SiO₄. Advanced Materials, 2004, 16(14): 1215–1218

[31] Epling W S , Hoflund G B , Salaita G N . Surface characterization study of the thermal decomposition of Ag₂CO₃. Journal of Physical Chemistry B, 1998, 102(12): 2263–2268

[32] Klacar S , Grönbeck H . H₂ dissociation over Ag/Al₂O₃: the first step in hydrogen assisted selective catalytic reduction of NO_x. Catalysis Science & Technology, 2013, 3(1): 183–190

[33] Gómez H , Rojas R , Patel D , Tabak L A , Lluch J M , Masgrau L . A computational and experimental study of O-glycosylation, catalysis by human UDP-GalNAc polypeptide: GalNAc transferase-T₂. Organic & Biomolecular Chemistry, 2014, 12(17): 2645–2655

[34] Dai R , Sun K , Shen R , Fang J , Cheong W C , Zhuang Z , Zhuang Z , Zhang C , Chen C . Direct microenvironment modulation of CO₂ electroreduction: negatively charged Ag sites going beyond catalytic surface reactions. Angewandte Chemie International Edition, 2024, 63(37): e202408580

[35] Chen C , Zheng Y , Zhan Y , Lin X , Zheng Q , Wei K . Enhanced Raman scattering and photocatalytic activity of Ag/ZnO heterojunction nanocrystals. Dalton Transactions, 2011, 40(37): 9566–9570

[36] Wen T , Liang L , Wang L , Shao Q , Zhang J , Long C . Adjusting Ag⁰ on oxygen-deficient Ag/MnO₂ through electronic metal-support interaction to enhance mineralization of toluene in post-plasma catalytic system. Chemical Engineering Journal, 2024, 493: 152572

[37] Zhang Z , Wen G , Luo D , Ren B , Zhu Y , Gao R , Dou H , Sun G , Feng M , Bai Z . . “Two ships in a bottle” design for Zn-Ag-O catalyst enabling selective and long-lasting CO₂ electroreduction. Journal of the American Chemical Society, 2021, 143(18): 6855–6864

[38] Aziz F F A , Timmiati S N , Jalil A A , Rusdan N A , Annuar N H R , Teh L P . Recent innovation on heterogeneous ZnO-based catalysts for enhanced CO₂ hydrogenation. Journal of Environmental Chemical Engineering, 2024, 12(3): 112976

[39] Xiao M , Wang L , Wang H , Yuan J , Chen X , Zhang Z , Fu X , Dai W . Oxygen vacancies stabilized Ag⁺ to enhance the performance of an Ag/In₂O₃ photocatalyst for non-oxidative coupling of methane. Catalysis Science & Technology, 2023, 13(14): 4148–4155

[40] Hu B , Yin Y , Liu G , Chen S , Hong X , Tsang S C E . Hydrogen spillover enabled active Cu sites for methanol synthesis from CO₂ hydrogenation over Pd doped CuZn catalysts. Journal of Catalysis, 2018, 359: 17–26

[41] Phongamwong T , Chantaprasertporn U , Witoon T , Numpilai T , Poo-arporn Y , Limphirat W , Donphai W , Dittanet P , Chareonpanich M , Limtrakul J . CO₂ hydrogenation to methanol over CuO-ZnO-ZrO₂-SiO₂ catalysts: effects of SiO₂ contents. Chemical Engineering Journal, 2017, 316: 692–703

[42] Li L , Mao D , Yu J , Guo X . Highly selective hydrogenation of CO₂ to methanol over CuO-ZnO-ZrO₂ catalysts prepared by a surfactant-assisted co-precipitation method. Journal of Power Sources, 2015, 279: 394–404

[43] Singha R K , Yadav A , Agrawal A , Shukla A , Adak S , Sasaki T , Bal R . Synthesis of highly coke resistant Ni nanoparticles supported MgO/ZnO catalyst for reforming of methane with carbon dioxide. Applied Catalysis B: Environment and Energy, 2016, 191: 165–178

[44] Jia X , Zhang X , Rui N , Hu X , Liu C J . Structural effect of Ni/ZrO₂ catalyst on CO₂ methanation with enhanced activity. Applied Catalysis B: Environment and Energy, 2019, 244: 159–169

[45] Chen C S , Cheng W H , Lin S S . Study of reverse water gas shift reaction by TPD, TPR, and CO₂ hydrogenation over potassium-promoted Cu/SiO₂ catalyst. Applied Catalysis A: General, 2003, 238(1): 55–67

[46] Kast P , Friedrich M , Girgsdies F , Kröhnert J , Teschner D , Lunkenbein T , Behrens M , Schlögl R . Strong metal-support interaction and alloying in Pd/ZnO catalysts for CO oxidation. Catalysis Today, 2016, 260: 21–31

[47] Liu L , Das S , Chen T , Dewangan N , Ashok J , Xi S , Borgna A , Li Z , Kawi S . Low temperature catalytic reverse water-gas shift reaction over perovskite catalysts in DBD plasma. Applied Catalysis B: Environment and Energy, 2020, 265: 118573

RIGHTS & PERMISSIONS

The Author(s) 2025