Abstract
Photocatalytic reduction of CO2 to natural gas using water vapor is a promising strategy for carbon recycling and renewable energy storage. However, the selectivity of current catalysts still remains a big challenge. Herein, we construct IrCu alloys on TiO2 nanosheets to promote photocatalytic CO2 to methane with 98.6% selectivity and 7.9% quantum efficiency at 365 nm under non-sacrificial ambient conditions. The performance is competitive with most other reported metal-based photocatalysts. Experimental and theoretical calculations demonstrate that the intensive H2O adsorption on Ir/TiO2 hinders *H transfer, inevitably generating the H2 by-product. Conversely, hydrophobic Cu effectively optimizes the interfacial hydrogen-bond network on IrCu/TiO2, predominantly in H-down configurations for H2O adsorption on the asymmetric charge-polarized Cuδ+-Irδ- structure, which facilitates the kinetic migration of dissociated *H to *CO-Cu sites, resulting in the reduced energy barrier for the key *CHO intermediate. This finding enables high CH4 selectivity on IrCu/TiO2, deepening our understanding of gas-solid interfacial water vapor in the enhanced natural gas synthesis.
Similar content being viewed by others
Data availability
The authors declare that all the data supporting the findings of this study are available within the article (and Supplementary Information Files), or available from the corresponding author on request. Source data are provided with this paper.
References
Tyne, R. et al. Rapid microbial methanogenesis during CO2 storage in hydrocarbon reservoirs. Nature 600, 670–674 (2021).
Hellerschmied, C. et al. Hydrogen storage and geo-methanation in a depleted underground hydrocarbon reservoir. Nat. Energy 9, 333–344 (2024).
Wei, Y. et al. A proposed global layout of carbon capture and storage in line with a 2 °C climate target. Nat. Clim. Chang. 11, 112–118 (2021).
Wu, J. et al. Regulated photocatalytic CO2-to-CH3OH pathway by synergetic dual active sites of interlayer. J. Am. Chem. Soc. 146, 26478–26484 (2024).
Li, J. et al. Structure-function relationship of p-block bismuth for selective photocatalytic CO2 reduction. Angew. Chem. Int. Ed. 63, e202407287 (2024).
Li, M. et al. Recent progress in solar-driven CO2 reduction to multicarbon products. Chem. Soc. Rev. 53, 9964–9975 (2024).
Li, J. et al. Self-adaptive dual-metal-site pairs in metal-organic frameworks for selective CO2 photoreduction to CH4. Nat. Catal. 4, 719–729 (2021).
Bi, F. et al. Engineering triple O-Ti-O vacancy associates for efficient water-activation catalysis. Nat. Commun. 16, 851 (2025).
Yoon, M. et al. 2D vacancy confinement in anatase TiO2 for enhanced photocatalytic activities. Adv. Mater. 37, 2413062 (2025).
Wu, M. et al. Photocatalytic oxidative coupling of methane to ethane using CO2 as a soft oxidant over the Au/TiO2-Vo nanosheets. Angew. Chem. Int. Ed. 64, e202414814 (2025).
Chen, C. et al. Efficient photoreduction of CO2 to CO with 100% selectivity by slowing down electron transport. J. Am. Chem. Soc. 146, 9163–9171 (2024).
Zhang, P. U. et al. Surface Ru-H bipyridine complexes-grafted TiO2 nanohybrids for efficient photocatalytic CO2 methanation. J. Am. Chem. Soc. 145, 5769–5777 (2023).
He, Y. et al. In situ fabrication of atomically adjacent dual-vacancy sites for nearly 100% selective CH4 production. Proc. Natl. Acad. Sci. USA. 121, e2322107121 (2024).
Jiang, Z. et al. Filling metal-organic framework mesopores with TiO2 for CO2 photoreduction. Nature 586, 549–554 (2020).
Du, P. et al. Interface-engineering-induced C-C coupling for C2H4 photosynthesis from atmospheric-concentration CO2 reduction. Angew. Chem. Int. Ed. 64, e202421353 (2025).
Barman, S. et al. Metal-free catalysis: a redox-active donor-acceptor conjugated microporous polymer for selective visible-light-driven CO2 reduction to CH4. J. Am. Chem. Soc. 143, 16284–16292 (2021).
Li, M. et al. Infrared photothermal catalytic reduction of atmospheric CO2 into CO with 100% selectivity via dual-plasmon resonance conductor. Adv. Mater. 37, 2503021 (2025).
Zou, W. et al. Metal-free photocatalytic CO2 reduction to CH4 and H2O2 under non-sacrificial ambient conditions. Angew. Chem. Int. Ed. 62, e202313392 (2023).
Geng, W. et al. Ternary metalation in a copper-covalent organic framework for tandem photocatalytic CO2 reduction with high selectivity. Angew. Chem. Int. Ed. 64, e202505546 (2025).
Liang, Y. et al. Efficient ethylene electrosynthesis through C-O cleavage promoted by water dissociation. Nat. Syn. 3, 1104–1112 (2024).
Zhu, C. et al. Engineering the coordination environment of metal centers for selective and high-current CO2 electromethanation. J. Am. Chem. Soc. 147, 26185–26194 (2025).
Gonella, G. et al. Water at charged interfaces. Nat. Rev. Chem. 5, 466–485 (2021).
Feng, J. et al. Modulating adsorbed hydrogen drives electrochemical CO2-to-C2 products. Nat. Commun. 14, 4615 (2023).
Xu, J. et al. Piezo-catalytic in-site H2O2 generation and activation across wide pH range to drive hydroxyl radical-mediated pollutant degradation. Nat. Commun. 16, 7908 (2025).
Gomes, R. H. et al. Modulating water hydrogen bonding within a non-aqueous environment controls its reactivity in electrochemical transformations. Nat. Catal. 7, 689–701 (2024).
Zhao, R. et al. Pd single atoms guided proton transfer along an interfacial hydrogen bond network for efficient electrochemical hydrogenation. Sci. Adv. 11, eadu1602 (2025).
Huang, Z. et al. Hydrogen-bonding-guided interfacial water engineering for selective CO2-to-C2+ conversion at industrial current densities. Adv. Funct. Mater. 36, e09330 (2026).
Ma, M. et al. Mechanistic insights into H2O dissociation in overall photo-/electrocatalytic CO2 reduction. Angew. Chem. Int. Ed. 64, e202425195 (2025).
Yun, T. Y. et al. Surface entropy mediated hydrogen spillover on Au/TiO2: influences of strongly adsorbed water on H2 adsorption thermodynamics. J. Am. Chem. Soc. 147, 29908–29918 (2025).
Liu, P. et al. Synergy between palladium single atoms and nanoparticles via hydrogen spillover for enhancing CO2 photoreduction to CH4. Adv. Mater. 34, 2200057 (2022).
Chen, X. et al. A highly efficient and regenerable Ir1-Cu1 dual-atom catalyst for low-temperature alkane dehydrogenation. Nat. Catal. 8, 436–447 (2025).
Tran, H. P. et al. Reactivity and stability of reduced Ir-weight TiO2-supported oxygen evolution catalysts for proton exchange membrane (PEM) water electrolyzer anodes. J. Am. Chem. Soc. 146, 31444–31455 (2024).
Li, W. et al. Support-accelerated proton transfer for enhanced oxygen evolution catalysis. J. Am. Chem. Soc. 147, 29505–29516 (2025).
Cao, X. et al. Sub-nano Ir-based alloy clusters by hierarchical confinement effect for water splitting. Angew. Chem. Int. Ed. 64, e202509993 (2025).
Park, Y. et al. Atomic-level Ru-Ir mixing in rutile-type (RuIr)O2 for efficient and durable oxygen evolution catalysis. Nat. Commun. 16, 579 (2025).
Lin, Z. et al. Positive and negative impacts of interfacial hydrogen bonds on photocatalytic hydrogen evolution. J. Am. Chem. Soc. 146, 22276–22283 (2024).
Ma, X. et al. Hydrogen-bond network promotes water splitting on the TiO2 surface. J. Am. Chem. Soc. 144, 13565–13573 (2022).
Yanagi, R. et al. Photocatalytic CO2 reduction with dissolved carbonates and near-Zero CO2 (aq) by employing long-range proton transport. J. Am. Chem. Soc. 145, 15381–15392 (2024).
Guo, H. et al. Ternary alloy Cu-Ru-Ir nanocages for acidic oxygen evolution reaction. ACS Nano 19, 35551–35561 (2025).
Ni, B. et al. Correlating oxidation state and surface ligand motifs with the selectivity of CO2 photoreduction to C2 products. Angew. Chem. Int. Ed. 62, e202215574 (2023).
Zhu, K. et al. Modulating Ti t2g orbital occupancy in a Cu/TiO2 composite for selective photocatalytic CO2 reduction to CO. Angew. Chem. Int. Ed. 61, e202207600 (2022).
Lee, B. et al. Electronic interaction between transition metal single-atoms and anatase TiO2 boosts CO2 photoreduction with H2O. Energy Environ. Sci. 15, 601 (2022).
Shen, Y. et al. Room-temperature photosynthesis of propane from CO2 with Cu single atoms on vacancy-rich TiO2. Nat. Commun. 14, 1117 (2023).
Wu, C. et al. Highly efficient photocatalytic CO2-to-CO on Ni-based cationic polymer with TiO2-assisted exfoliation and stabilization. Angew. Chem. Int. Ed. 64, e202423200 (2025).
Li, T. et al. Asymmetrical degree engineered carbon dioxide photoreduction for single atomic Co sites on polymeric carbon nitride. Adv. Funct. Mater. 35, e11356 (2025).
Chen, C. et al. Spatially separated redox centers in anthraquinone-grafted metal organic frameworks for efficient piezo-photocatalytic H2O2 production. Angew. Chem. Int. Ed. 64, e202425656 (2025).
Li, Q. et al. Ag-Pt alloy nanoparticles modified Zn-based nanosheets for highly selective CO2 photoreduction to CH4. Adv. Funct. Mater. 35, 2416975 (2025).
Cheng, L. et al. Dual-single-atom tailoring with bifunctional integration for high-performance CO2 photoreduction. Adv. Mater. 33, 2105135 (2021).
Cao, Y. et al. Modulating electron density of vacancy site by single Au atom for effective CO2 photoreduction. Nat. Commun. 12, 1675 (2021).
Lei, J. et al. Visible light-driven acetaldehyde production from CO2 and H2O via synergistic vacancies and atomically dispersed Cu sites. Angew. Chem. Int. Ed. 64, e202422667 (2025).
Bai, W. et al. Pd-N4 sites in MOFs modulate oxygen reduction pathways for 100% selective photocatalytic CO2 -to-CH4 conversion from oxygenated flue gas. Angew. Chem. Int. Ed. 64, e202513157 (2025).
Long, R. et al. Isolation of Cu atoms in Pd lattice: forming highly selective sites for photocatalytic conversion of CO2 to CH4. J. Am. Chem. Soc. 139, 4486–4492 (2017).
Dong, Y. et al. Advancing CO2 to CH4 conversion: the pivotal role of RuCu alloy in crystalline red phosphorus photocatalysis. Appl. Catal. B Environ. 357, 124347 (2024).
Cheng, L. et al. Site-specific electron-driving observations of CO2-to-CH4 photoreduction on Co-doped CeO2/crystalline carbon nitride S-Scheme heterojunctions. Adv. Mater. 34, 2200929 (2022).
Feng, C. et al. Ru-Ov site-mediated product selectivity switch for overall photocatalytic CO2 reduction. Adv. Mater. 37, 2411813 (2025).
Zhang, M. et al. Promoting photocatalytic CO2 methanation by the construction of cooperative copper dual-active sites. ACS Catal. 14, 5275–5285 (2024).
Li, M. et al. Engineering spatially adjacent redox sites with synergistic spin polarization effect to boost photocatalytic CO2 methanation. J. Am. Chem. Soc. 146, 15538–15548 (2024).
Ma, Y. et al. Selective photocatalytic CO2 reduction in aerobic environment by microporous Pd-porphyrin-based polymers coated hollow TiO2. Nat. Commun. 13, 1400 (2022).
Zhang, L. et al. Bimetallic nanoalloys planted on super-hydrophilic carbon nanocages featuring tip-intensified hydrogen evolution electrocatalysis. Nat. Commun. 15, 7179 (2024).
Li, Y. et al. Enhancement of nitrate-to-ammonia on amorphous CeOx-modified Cu via tuning of active hydrogen supply. Adv. Energy Mater. 14, 2303863 (2024).
Huang, S. et al. Spillover-mediated H* redistribution promotes electrocatalytic acetonitrile hydrogenation in PEM reactors. Angew. Chem. Int. Ed. 64, e202512654 (2025).
Li, P. et al. Revealing the role of double-layer microenvironments in pH-dependent oxygen reduction activity over metal-nitrogen-carbon catalysts. Nat. Commun. 14, 6926 (2023).
Huang, G. et al. Multisite-steered C-C coupling for photocatalytic air-concentration CO2 reduction into C2H6. Sci. China Mater. https://doi.org/10.1007/s40843-025-3464-4 (2025).
Liu, B. et al. Simultaneous value-added utilization of photogenerated electrons and holes on Pd/TiO2. Nat. Commun. 16, 6014 (2025).
Kresse, G. et al. Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set. Comp. Mater. Sci. 6, 15–50 (1996).
Perdew, J. P. et al. Generalized gradient approximation made simple. Phys. Rev. Lett. 77, 3865 (1996).
Peterson, A. A. et al. How copper catalyzes the electroreduction of carbon dioxide into hydrocarbon fuels. Energy Environ. Sci. 3, 1311–1315 (2010).
Woo, T. K. et al. A combined car-parrinello QM/MM implementation for ab initio molecular dynamics simulations of extended systems: application to transition metal catalysis. J. Phys. Chem. B 101, 7877–7880 (1997).
Acknowledgements
This work was supported by the National Natural Science Foundation of China (62375120, W.Z.), (22476084, H.W.), and Natural Science Foundation of Jiangsu Province of China (BK20240171, W.Z.), and (BK20231513, L.D.).
Author information
Authors and Affiliations
Contributions
Z.L., W.Z., H.W. and C.Y. conceived the research idea. C.Y. performed the experiments and analyzed the data. Z.L. carried out the DFT and AIMD calculations. Z.S. and K.T. assisted in the experimental process. C.Y., W.Z., H.W., Z.L. and L.D. co-wrote and revised the paper; all authors discussed the results and commented on the paper.
Corresponding authors
Ethics declarations
Competing interests
The authors declare no competing interests.
Peer review
Peer review information
Nature Communications thanks Yongjie Wang and the other anonymous reviewer(s) for their contribution to the peer review of this work. A peer review file is available.
Additional information
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Source data
Rights and permissions
Open Access This article is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License, which permits any non-commercial use, sharing, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if you modified the licensed material. You do not have permission under this licence to share adapted material derived from this article or parts of it. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by-nc-nd/4.0/.
About this article
Cite this article
Yin, C., Sun, Z., Tang, K. et al. Asymmetric charge-polarization tailoring active hydrogen transfer for selective photoreduction CO2 to CH4. Nat Commun (2026). https://doi.org/10.1038/s41467-026-71695-3
Received:
Accepted:
Published:
DOI: https://doi.org/10.1038/s41467-026-71695-3
