- 1.
Statista Research Department Production Capacity of Ammonia Worldwide from 2018 to 2021, with a Forecast for 2026 and 2030. Online 2023, 2030, 2030.
- 2.
Ye, D.; Tsang, S.C.E. Prospects and Challenges of Green Ammonia Synthesis. Nat. Synth. 2023, 2, 612–623. https://doi.org/10.1038/s44160-023-00321-7.
- 3.
Kyriakou, V.; Garagounis, I.; Vourros, A.; et al. An Electrochemical Haber-Bosch Process. Joule 2020, 4, 142–158. https://doi.org/10.1016/j.joule.2019.10.006.
- 4.
Mateo, D.; Cerrillo, J.L.; Durini, S.; et al. Fundamentals and Applications of Photo-Thermal Catalysis. Chem. Soc. Rev. 2021, 50, 2173–2210. https://doi.org/10.1039/d0cs00357c.
- 5.
Huang, P.W.; Hatzell, M.C. Prospects and Good Experimental Practices for Photocatalytic Ammonia Synthesis. Nat. Commun. 2022, 13, 7908. https://doi.org/10.1038/s41467-022-35489-7.
- 6.
Garvey, S.M.; Davidson, E.A.; Wagner-riddle, C.; et al. Emerging Opportunities and Research Questions for Green Ammonia Adoption in Agriculture and Beyond. Nat. Rev. Clean Technol. 2025, 1, 10–11. https://doi.org/10.1038/s44359-024-00012-2.
- 7.
Usubharatana, P.; McMartin, D.; Veawab, A.; et al. Photocatalytic Process for CO2 Emission Reduction from Industrial Flue Gas Streams. Ind. Eng. Chem. Res. 2006, 45, 2558–2568. https://doi.org/10.1021/ie0505763.
- 8.
Sun, X.; Jiang, S.; Huang, H.; et al. Solar Energy Catalysis. Angew. Chem. 2022, 134, e202204880. https://doi.org/10.1002/ange.202204880.
- 9.
Beil, S.B.; Bonnet, S.; Casadevall, C.; et al. Challenges and Future Perspectives in Photocatalysis: Conclusions from an Interdisciplinary Workshop. JACS Au 2024, 4, 2746–2766. https://doi.org/10.1021/jacsau.4c00527.
- 10.
Qu, Y.; Duan, X. Progress, Challenge and Perspective of Heterogeneous Photocatalysts. Chem. Soc. Rev. 2013, 42, 2568–2580. https://doi.org/10.1039/c2cs35355e.
- 11.
Luo, S.; Ren, X.; Lin, H.; et al. Plasmonic Photothermal Catalysis for Solar-to-Fuel Conversion: Current Status and Prospects. Chem. Sci. 2021, 12, 5701–5719. https://doi.org/10.1039/d1sc00064k.
- 12.
Zhang, J.; Chen, H.; Duan, X.; et al. Photothermal Catalysis: From Fundamentals to Practical Applications. Mater. Today 2023, 68, 234–253. https://doi.org/10.1016/j.mattod.2023.06.017.
- 13.
Song, C.; Wang, Z.; Yin, Z.; et al. Principles and Applications of Photothermal Catalysis. Chem Catal. 2022, 2, 52–83. https://doi.org/10.1016/j.checat.2021.10.005.
- 14.
Mateo, D.; Sousa, A.; Zakharzhevskii, M.; et al. Challenges and Opportunities for the Photo-(Thermal) Synthesis of Ammonia. Green Chem. 2023, 26, 1041–1061. https://doi.org/10.1039/d3gc02996d.
- 15.
Zhang, Z.; Hu, X. Visible-Light-Driven Catalytic Deracemization of Secondary Alcohols. Angew. Chem. 2021, 133, 23015–23020. https://doi.org/10.1002/ange.202107570.
- 16.
Ziegenbalg, D.; Pannwitz, A.; Rau, S.; et al. Comparative Evaluation of Light-Driven Catalysis: A Framework for Standardized Reporting of Data**. Angew. Chem. Int. Ed. 2022, 61, e202114106. https://doi.org/10.1002/anie.202114106.
- 17.
Khan, I.S.; Garzon-Tovar, L.; Mateo, D.; et al. Metal-Organic-Frameworks and Their Derived Materials in Photo-Thermal Catalysis. Eur. J. Inorg. Chem. 2022, 2022, e202200316. https://doi.org/10.1002/ejic.202200316.
- 18.
Schlögl, R. Catalytic Synthesis of Ammonia-A “Never-Ending Story”? Angew. Chem. Int. Ed. 2003, 42, 2004–2008. https://doi.org/10.1002/anie.200301553.
- 19.
Liu, H. Ammonia Synthesis Catalyst 100 Years: Practice, Enlightenment and Challenge. Cuihua Xuebao/Chin. J. Catal. 2014, 35, 1619–1640. https://doi.org/10.1016/S1872-2067(14)60118-2.
- 20.
Ozaki, A. Development of Alkali-Promoted Ruthenium Catalyst for Ammonia Synthesis. Acc. Chem. Res. 1981, 14, 16–21.
- 21.
Hellman, A.; Honkala, K.; Remediakis, I.N.; et al. Ammonia Synthesis and Decomposition on a Ru-Based Catalyst Modeled by First-Principles. Surf. Sci. 2009, 603, 1731–1739. https://doi.org/10.1016/j.susc.2008.10.059.
- 22.
Zhou, Y.; Wang, J.; Liang, L.; et al. Unraveling the Size-Dependent Effect of Ru-Based Catalysts on Ammonia Synthesis at Mild Conditions. J. Catal. 2021, 404, 501–511. https://doi.org/10.1016/j.jcat.2021.10.024.
- 23.
Fang, H.; Liu, D.; Luo, Y.; et al. Challenges and Opportunities of Ru-Based Catalysts toward the Synthesis and Utilization of Ammonia. ACS Catal. 2022, 12, 3938–3954. https://doi.org/10.1021/acscatal.2c00090.
- 24.
Zhang, T.; Zhang, X.; Chang, F. Synergistic Photothermal Acceleration of Ammonia Synthesis Using Defective TiO2 Supported Ru Catalysts. Ind. Eng. Chem. Res. 2025, 64, 14879–14887. https://doi.org/10.1021/acs.iecr.5c02153.
- 25.
Vieri, H.M.; Badakhsh, A.; Choi, S.H. Comparative Study of Ba, Cs, K, and Li as Promoters for Ru/La2Ce2O7-Based Catalyst for Ammonia Synthesis. Int. J. Energy Res. 2023, 2023, 2072245. https://doi.org/10.1155/2023/2072245.
- 26.
Altenburg, K. The Role of Potassium as a Promoter in Iron Catalysts for Ammonia Synthesis. J. Catal. 1980, 66, 326–334. https://doi.org/10.1016/0021-9517(80)90037-8.
- 27.
Peng, X.; Luo, Y.; Zhang, T.; et al. Potassium Promoter Regulates Electronic Structure and Hydrogen Spillover of Ultrasmall Ru Nanoclusters Catalyst for Ammonia Synthesis. Chem. Eng. Sci. 2024, 292, 120021. https://doi.org/10.1016/j.ces.2024.120021.
- 28.
Ye, T.N.; Park, S.W.; Lu, Y.; et al. Vacancy-Enabled N2 Activation for Ammonia Synthesis on an Ni-Loaded Catalyst. Nature 2020, 583, 391–395. https://doi.org/10.1038/s41586-020-2464-9.
- 29.
Zhuang, G.; Chen, Y.; Zhuang, Z.; et al. Oxygen Vacancies in Metal Oxides: Recent Progress towards Advanced Catalyst Design. Sci. China Mater. 2020, 63, 2089–2118. https://doi.org/10.1007/s40843-020-1305-6.
- 30.
Huang, Y.; Yu, Y.; Yu, Y.; et al. Oxygen Vacancy Engineering in Photocatalysis. Sol. RRL 2020, 4, 2000037. https://doi.org/10.1002/solr.202000037.
- 31.
Humphreys, J.; Lan, R.; Chen, S.; et al. Improved Stability and Activity of Fe-Based Catalysts through Strong Metal Support Interactions Due to Extrinsic Oxygen Vacancies in Ce0.8Sm0.2O2-δ: Δfor the Efficient Synthesis of Ammonia. J. Mater. Chem. A 2020, 8, 16676–16689. https://doi.org/10.1039/d0ta05238h.
- 32.
Nakaji, Y.; Kobayashi, D.; Nakagawa, Y.; et al. Mechanism of Formation of Highly Dispersed Metallic Ruthenium Particles on Ceria Support by Heating and Reduction. J. Phys. Chem. C 2019, 123, 20817–20828. https://doi.org/10.1021/acs.jpcc.9b00515.
- 33.
Liu, Z.; Zhang, F.; Rui, N.; et al. Highly Active Ceria-Supported Ru Catalyst for the Dry Reforming of Methane: In Situ Identification of Ruδ+-Ce3+ Interactions for Enhanced Conversion. ACS Catal. 2019, 9, 3349–3359. https://doi.org/10.1021/acscatal.8b05162.
- 34.
Li, C.; Shi, Y.; Zhang, Z.; et al. Improving the Ammonia Synthesis Activity of Ru/CeO2 through Enhancement of the Metal–Support Interaction. J. Energy Chem. 2021, 60, 403–409. https://doi.org/10.1016/j.jechem.2021.01.031.
- 35.
Lin, B.; Fang, B.; Wu, Y.; et al. Enhanced Ammonia Synthesis Activity of Ceria-Supported Ruthenium Catalysts Induced by CO Activation. ACS Catal. 2021, 11, 1331–1339. https://doi.org/10.1021/acscatal.0c05074.
- 36.
Zhang, Z.Y.; Yao, J.L.; Pan, Y.Q.; et al. Strong Metal-Support Interaction Induced Excellent Performance for Photo-Thermal Catalysis Methane Dry Reforming over Ru-Cluster-Ceria Catalyst. Nano Energy 2025, 133, 110474. https://doi.org/10.1016/j.nanoen.2024.110474.
- 37.
Kammert, J.; Moon, J.; Wu, Z. A Review of the Interactions between Ceria and H2 and the Applications to Selective Hydrogenation of Alkynes. Chin. J. Catal. 2020, 41, 901–914. https://doi.org/10.1016/S1872-2067(19)63509-6.
- 38.
Lin, B.; Liu, Y.; Heng, L.; et al. Morphology Effect of Ceria on the Catalytic Performances of Ru/CeO2 Catalysts for Ammonia Synthesis. Ind. Eng. Chem. Res. 2018, 57, 9127–9135. https://doi.org/10.1021/acs.iecr.8b02126.
- 39.
Liu, P.; Niu, R.; Li, W.; et al. Morphology Effect of Ceria on the Ammonia Synthesis Activity of Ru/CeO2 Catalysts. Catal. Lett. 2019, 149, 1007–1016. https://doi.org/10.1007/s10562-019-02674-1.
- 40.
Su, K.; Huang, D.; Fang, H.; et al. Boosting N2 Conversion into NH3 over Ru Catalysts via Modulating the Ru-Promoter Interface. ACS Appl. Mater. Interfaces 2023, 15, 56992–57002. https://doi.org/10.1021/acsami.3c12531.
- 41.
Wang, Z.; Huang, Z.; Brosnahan, J.T.; et al. Ru/CeO2 Catalyst with Optimized CeO2 Support Morphology and Surface Facets for Propane Combustion. Environ. Sci. Technol. 2019, 53, 5349–5358. https://doi.org/10.1021/acs.est.9b01929.
- 42.
Gao, Y.; Li, R.; Chen, S.; et al. Morphology-Dependent Interplay of Reduction Behaviors, Oxygen Vacancies and Hydroxyl Reactivity of CeO2 Nanocrystals. Phys. Chem. Chem. Phys. 2015, 17, 31862–31871. https://doi.org/10.1039/c5cp04570c.
- 43.
Liu, K.; Sun, Y.; Feng, J.; et al. Intensified Gas-Phase Hydrogenation of Acetone to Isopropanol Catalyzed at Metal-Oxide Interfacial Sites. Chem. Eng. J. 2023, 454, 140059. https://doi.org/10.1016/j.cej.2022.140059.
- 44.
Sun, H.; Zhang, Y.; Wang, C.; et al. Integrated Carbon Capture and Utilization: Synergistic Catalysis between Highly Dispersed Ni Clusters and Ceria Oxygen Vacancies. Chem. Eng. J. 2022, 437, 135394. https://doi.org/10.1016/j.cej.2022.135394.
- 45.
Morgan, D.J. Resolving Ruthenium: XPS Studies of Common Ruthenium Materials. Surf. Interface Anal. 2015, 47, 1072–1079. https://doi.org/10.1002/sia.5852.
- 46.
Ma, Z.; Zhao, S.; Pei, X.; et al. New Insights into the Support Morphology-Dependent Ammonia Synthesis Activity of Ru/CeO2 Catalysts. Catal. Sci. Technol. 2017, 7, 191–199. https://doi.org/10.1039/C6CY02089E.
- 47.
Rakhmatullin, R.M.; Semashko, V.V.; Korableva, S.L.; et al. EPR Study of Ceria Nanoparticles Containing Different Concentration of Ce3+ Ions. Mater. Chem. Phys. 2018, 219, 251–257. https://doi.org/10.1016/j.matchemphys.2018.08.028.
- 48.
Elmutasim, O.; Hussien, A.G.; Sharan, A.; et al. Evolution of Oxygen Vacancy Sites in Ceria-Based High-Entropy Oxides and Their Role in N2 Activation. ACS Appl. Mater. Interfaces, 2024, 16, 23038–23053. https://doi.org/10.1021/acsami.3c16521.
- 49.
Ho, C.; Yu, J.C.; Kwong, T.; et al. Morphology-Controllable Synthesis of Mesoporous CeO2 Nano- and Microstructures. Chem. Mater. 2005, 17, 4514–4522. https://doi.org/10.1021/cm0507967.
- 50.
Li, X.; Zhang, X.; Everitt, H.O.; et al. Light-Induced Thermal Gradients in Ruthenium Catalysts Significantly Enhance Ammonia Production. Nano Lett. 2019, 19, 1706–1711. https://doi.org/10.1021/acs.nanolett.8b04706.
- 51.
Sousa, A.; Mateo, D.; Garzon-Tovar, L.; et al. Unlocking Low-Temperature Ammonia Decomposition via an Iron Metal–Organic Framework-Derived Catalyst Under Photo-Thermal Conditions. Small 2025, 21, 2411468. https://doi.org/10.1002/smll.202411468.
- 52.
Bauer, C.; Abid, J.P.; Fermin, D.; et al. Ultrafast Chemical Interface Scattering as an Additional Decay Channel for Nascent Nonthermal Electrons in Small Metal Nanoparticles. J. Chem. Phys. 2004, 120, 9302–9315. https://doi.org/10.1063/1.1710856.
- 53.
Liu, B.; Wu, H.; Parkin, I.P. Gaseous Photocatalytic Oxidation of Formic Acid over TiO2: A Comparison between the Charge Carrier Transfer and Light-Assisted Mars–van Krevelen Pathways. J. Phys. Chem. C 2019, 123, 22261–22272. https://doi.org/10.1021/acs.jpcc.9b05357.
- 54.
Xie, B.; Hu, D.; Kumar, P.; et al. Heterogeneous Catalysis via Light-Heat Dual Activation: A Path to the Breakthrough in C1 Chemistry. Joule 2024, 8, 312–333. https://doi.org/10.1016/j.joule.2023.12.013.
- 55.
Collado, L.; Pizarro, A.H.; Barawi, M.; et al. Light-Driven Nitrogen Fixation Routes for Green Ammonia Production. Chem. Soc. Rev. 2024, 53, 11334–11389 https://doi.org/10.1039/d3cs01075a.
- 56.
Mao, C.; Li, H.; Gu, H.; et al. Beyond the Thermal Equilibrium Limit of Ammonia Synthesis with Dual Temperature Zone Catalyst Powered by Solar Light. Chem 2019, 5, 2702–2717. https://doi.org/10.1016/j.chempr.2019.07.021.
- 57.
Zheng, J.; Lu, L.; Lebedev, K.; et al. Fe on Molecular-Layer MoS2 as Inorganic Fe-S2-Mo Motifs for Light-Driven Nitrogen Fixation to Ammonia at Elevated Temperatures. Chem Catal. 2021, 1, 162–182. https://doi.org/10.1016/j.checat.2021.03.002.
- 58.
Zhao, Y.; Miao, Y.; Zhou, C.; et al. Artificial Photocatalytic Nitrogen Fixation: Where Are We Now? Where Is Its Future? Mol. Catal. 2022, 518, 112107. https://doi.org/10.1016/j.mcat.2021.112107.
- 59.
Choudhury, B.; Chetri, P.; Choudhury, A. Oxygen Defects and Formation of Ce3+ Affecting the Photocatalytic Performance of CeO2 Nanoparticles. RSC Adv. 2014, 4, 4663–4671. https://doi.org/10.1039/c3ra44603d.
- 60.
Peng, Y.; Albero, J.; Franconetti, A.; et al. Visible and NIR Light Assistance of the N2 Reduction to NH3 Catalyzed by Cs-Promoted Ru Nanoparticles Supported on Strontium Titanate. ACS Catal. 2022, 12, 4938–4946. https://doi.org/10.1021/acscatal.2c00509.
- 61.
Rivera Rocabado, D.S.; Noguchi, T.G.; Hayashi, S.; et al. Adsorption States of N2/H2 Activated on Ru Nanoparticles Uncovered by Modulation-Excitation Infrared Spectroscopy and Density Functional Theory Calculations. ACS Nano 2021, 15, 20079–20086. https://doi.org/10.1021/acsnano.1c07825.
- 62.
Lin, B.; Wu, Y.; Fang, B.; et al. Ru Surface Density Effect on Ammonia Synthesis Activity and Hydrogen Poisoning of Ceria-Supported Ru Catalysts. Chin. J. Catal. 2021, 42, 1712–1723. https://doi.org/10.1016/S1872-2067(20)63787-1.
- 63.
Liu, P.; Huang, Z.; Yang, S.; et al. Support Amorphization Engineering Regulates Single-Atom Ru as an Electron Pump for Nitrogen Photofixation. ACS Catal. 2022, 12, 8139–8146. https://doi.org/10.1021/acscatal.2c01704.
- 64.
Li, X.H.; Li, H.; Jiang, S.L.; et al. Constructing Mimic-Enzyme Catalyst: Polyoxometalates Regulating Carrier Dynamics of Metal-Organic Frameworks to Promote Photocatalytic Nitrogen Fixation. ACS Catal. 2023, 13, 7189–7198. https://doi.org/10.1021/acscatal.3c00944.
- 65.
Feng, C.; Raziq, F.; Hu, M.; et al. Photoexcitation Altered Reaction Pathway Greatly Facilitate Ammonia Synthesis Over Isolated Ru Sites. Adv. Energy Mater. 2024, 14, 2303792. https://doi.org/10.1002/aenm.202303792.
- 66.
Ooya, K.; Li, J.; Fukui, K.; et al. Ruthenium Catalysts Promoted by Lanthanide Oxyhydrides with High Hydride-Ion Mobility for Low-Temperature Ammonia Synthesis. Adv. Energy Mater. 2021, 11, 2003723. https://doi.org/10.1002/aenm.202003723.
- 67.
Wang, Y.; Zhou, Y.; Huang, Y.; et al. Mechanistic Insights into Evolution of Schottky Junctions on Metal Nanoparticle-Loaded Mo-Doped TiO2 for Enhanced Photothermal Ammonia Catalysis. Chem. Eng. J. 2025, 517, 164377
- 68.
Wang, Y.; Huang, L.; Zhang, T.C.; et al. Visible-Light-Induced Photocatalytic Oxidation of Gaseous Ammonia on Mo, c-Codoped TiO2: Synthesis, Performance and Mechanism. Chem. Eng. J. 2024, 482, 148811. https://doi.org/10.1016/j.cej.2024.148811.
- 69.
Peng, Y.; Melillo, A.; Shi, R.; et al. Light-Assistance in Nitrogen Fixation to Ammonia by Highly Dispersed Cs-Promoted Ru Clusters Supported on ZrO2. Appl. Catal. B Environ. 2023, 339, 123143. https://doi.org/10.1016/j.apcatb.2023.123143.
- 70.
Yang, Y.; Wang, P.; Zhang, X.; et al. Regulating the Scaling Relations in Ammonia Synthesis through a Light-Driven Bendable Seesaw Effect on Tailored Iron Catalyst. Angew. Chem. 2024, 136, e202408309.
- 71.
Sousa, A.; Rendon Patino, A.; Garzon Tovar, L.; et al. Ammonia Decomposition via MOF-Derived Photothermal Catalysts. ChemSusChem 2025, 18, e202401896. https://doi.org/10.1002/cssc.202401896.
- 72.
Bian, X.; Zhao, Y.; Waterhouse, G.I.N.; et al. Quantifying the Contribution of Hot Electrons in Photothermal Catalysis: A Case Study of Ammonia Synthesis over Carbon‐supported Ru Catalyst. Angew. Chem. Int. Ed. 2023, 62, e202304452. https://doi.org/10.1002/anie.202304452.
- 73.
Mao, C.; Wang, J.; Zou, Y.; et al. Photochemical Acceleration of Ammonia Production by Pt1-Ptn-TiN Reduction and N2 Activation. J. Am. Chem. Soc. 2023, 145, 13134–13146. https://doi.org/10.1021/jacs.3c01947.
- 74.
Li, X.K.; Ji, W.J.; Zhao, J.; et al. Ammonia Decomposition over Ru and Ni Catalysts Supported on Fumed SiO2, MCM-41, and SBA-15. J. Catal. 2005, 236, 181–189. https://doi.org/10.1016/j.jcat.2005.09.030.
- 75.
Yin, S.F.; Xu, B.Q.; Zhu, W.X.; et al. Carbon Nanotubes-Supported Ru Catalyst for the Generation of COx-Free Hydrogen from Ammonia. Catal. Today 2004, 93–95, 27–38. https://doi.org/10.1016/j.cattod.2004.05.011.
- 76.
Duan, X.; Zhou, J.; Qian, G.; et al. Carbon Nanofiber-Supported Ru Catalysts for Hydrogen Evolution by Ammonia Decomposition. Cuihua Xuebao/Chin. J. Catal. 2010, 31, 979–986. https://doi.org/10.1016/s1872-2067(10)60097-6.
- 77.
Yin, S.F.; Zhang, Q.H.; Xu, B.Q.; et al. Investigation on the Catalysis of COx-Free Hydrogen Generation from Ammonia. J. Catal. 2004, 224, 384–396. https://doi.org/10.1016/j.jcat.2004.03.008.
- 78.
Yin, S.F.; Xu, B.Q.; Wang, S.J.; et al. Magnesia-Carbon Nanotubes (MgO-CNTs) Nanocomposite: Novel Support of Ru Catalyst for the Generation of COx-Free Hydrogen from Ammonia. Catal. Lett. 2004, 96, 113–116. https://doi.org/10.1023/B:CATL.0000030107.64702.74.
- 79.
Rendon-Patiño, A.; Mateo, D.; Duran-Uribe, S.; et al. Ruthenium Nanoparticles within Carbon Spheres for Efficient Ammonia Decomposition. ChemCatChem 2024, 93, 27–38. https://doi.org/10.1002/cctc.202400878.