Enhanced photocatalytic alkane production from fatty acid decarboxylation via inhibition of radical oligomerization


The decarboxylation of bio-derived fatty acids provides a sustainable pathway for the production of alkane products under mild conditions; however, products are generally obtained in low selectivity due to the uncontrollable reactivity of radical intermediates. Here we demonstrate that photogenerated radicals can be rapidly terminated by surface hydrogen species during photocatalytic decarboxylation of fatty acids on a hydrogen-rich surface that is constructed by the interactions between H2 and Pt/TiO2 catalyst, thereby greatly inhibiting oligomerization; Cn1 alkanes can therefore be obtained from bio-derived C12–C18 fatty acids in high yields (≥90%) under mild conditions (30 °C, H2 pressure ≤0.2 MPa) and 365 nm light-emitting dode irradiation. Industrial low-value fatty acid mixtures (namely, soybean and tall oil fatty acids) can be transformed into alkane products in high yields (up to 95%). Our research introduces an efficient biomass-upgrading approach that is enabled by subtle control of the radical intermediate conversion on a heterogeneous surface.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Fig. 1: A schematic representation of a photocatalytic decarboxylation strategy for the production of alkanes from bio-derived fatty acids.
Fig. 2: Photocatalytic decarboxylation of saturated fatty acids.
Fig. 3: The interaction between H2 and Pt/TiO2 and its influence on the production of Cn1 alkanes.
Fig. 4: Photocatalytic decarboxylation of unsaturated fatty acids and fatty acid mixtures over Pt/TiO2.

Data availability

The data that support the plots within this paper and other findings of this study are available from the corresponding author on reasonable request.


  1. 1.

    Anthonykutty, J. M. et al. Value added hydrocarbons from distilled tall oil via hydrotreating over a commercial NiMo catalyst. Ind. Eng. Chem. Res. 52, 10114–10125 (2013).

  2. 2.

    Kunkes, E. L. et al. Catalytic conversion of biomass to monofunctional hydrocarbons and targeted liquid-fuel classes. Science 322, 417–421 (2008).

  3. 3.

    Deneyer, A. et al. Direct upstream integration of biogasoline production into current light straight run naphtha petrorefinery processes. Nat. Energy 3, 969–977 (2018).

  4. 4.

    Luo, N. et al. Visible-light-driven coproduction of diesel precursors and hydrogen from lignocellulose-derived methylfurans. Nat. Energy 4, 575–584 (2019).

  5. 5.

    Zhao, C., Brück, T. & Lercher, J. A. Catalytic deoxygenation of microalgae oil to green hydrocarbons. Green. Chem. 15, 1720–1739 (2013).

  6. 6.

    Lestari, S., Maki-Arvela, P., Beltramini, J., Lu, G. Q. & Murzin, D. Y. Transforming triglycerides and fatty acids into biofuels. ChemSusChem 2, 1109–1119 (2009).

  7. 7.

    Abdul Kapor, N. Z., Maniam, G. P., Rahim, M. H. A. & Yusoff, M. M. Palm fatty acid distillate as a potential source for biodiesel production-a review. J. Clean. Prod. 143, 1–9 (2017).

  8. 8.

    Haas, M. J. Improving the economics of biodiesel production through the use of low value lipids as feedstocks: vegetable oil soapstock. Fuel Process. Technol. 86, 1087–1096 (2005).

  9. 9.

    Mäki-Arvela, P. et al. Catalytic deoxygenation of tall oil fatty acid over palladium supported on mesoporous carbon. Energy Fuels 25, 2815–2825 (2011).

  10. 10.

    Gosselink, R. W. et al. Reaction pathways for the deoxygenation of vegetable oils and related model compounds. ChemSusChem 6, 1576–1594 (2013).

  11. 11.

    Zhang, J. & Zhao, C. Development of a bimetallic Pd-Ni/HZSM-5 catalyst for the tandem limonene dehydrogenation and fatty acid deoxygenation to alkanes and arenes for use as biojet fuel. ACS Catal. 6, 4512–4525 (2016).

  12. 12.

    Snåre, M., Kubičková, I., Mäki-Arvela, P., Eränen, K. & Murzin, D. Y. Heterogeneous catalytic deoxygenation of stearic acid for production of biodiesel. Ind. Eng. Chem. Res. 45, 5708–5715 (2006).

  13. 13.

    Zhang, Z. et al. Catalytic decarbonylation of stearic acid to hydrocarbons over activated carbon-supported nickel. Sustain. Energy Fuels 2, 1837–1843 (2018).

  14. 14.

    Peng, B., Yuan, X., Zhao, C. & Lercher, J. A. Stabilizing catalytic pathways via redundancy: selective reduction of microalgae oil to alkanes. J. Am. Chem. Soc. 134, 9400–9405 (2012).

  15. 15.

    Schwarz, J. & König, B. Decarboxylative reactions with and without light—a comparison. Green. Chem. 20, 323–361 (2018).

  16. 16.

    Kraeutler, B. & Bard, A. J. Heterogeneous photocatalytic decomposition of saturated carboxylic acids on titanium dioxide powder. Decarboxylative route to alkanes. J. Am. Chem. Soc. 100, 5985–5992 (1978).

  17. 17.

    Heciak, A., Morawski, A. W., Grzmil, B. & Mozia, S. Cu-modified TiO2 photocatalysts for decomposition of acetic acid with simultaneous formation of C1–C3 hydrocarbons and hydrogen. Appl. Catal. B 140-141, 108–114 (2013).

  18. 18.

    Betts, L. M., Dappozze, F. & Guillard, C. Understanding the photocatalytic degradation by P25 TiO2 of acetic acid and propionic aicd in the pursuit of alkane production. Appl. Catal. A 554, 35–43 (2018).

  19. 19.

    Ngo, S. et al. Kinetics and mechanism of the photocatalytic degradation of acetic acid in absence or presence of O2. J. Photochem. Photobiol. A 339, 80–88 (2017).

  20. 20.

    Holzhäuser, F. J. et al. Electrochemical cross-coupling of biogenic di-acids for sustainable fuel production. Green. Chem. 21, 2334–2344 (2019).

  21. 21.

    Manley, D. W. et al. Unconventional titania photocatalysis: direct deployment of carboxylic acids in alkylations and annulations. J. Am. Chem. Soc. 134, 13580–13583 (2012).

  22. 22.

    Manley, D. W. & Walton, J. C. A clean and selective radical homocoupling employing carboxylic acids with titania photoredox catalysis. Org. Lett. 16, 5394–5397 (2014).

  23. 23.

    dos Santos, T. R., Harnisch, F., Nilges, P. & Schroder, U. Electrochemistry for biofuel generation: transformation of fatty acids and triglycerides to diesel-like olefin/ether mixtures and olefins. ChemSusChem 8, 886–893 (2015).

  24. 24.

    Creusen, G., Holzhäuser, F. J., Artz, J., Palkovits, S. & Palkovits, R. Producing widespread monomers from biomass using economical carbon and ruthenium–titanium dioxide electrocatalysts. ACS Sustain. Chem. Eng. 6, 17108–17113 (2018).

  25. 25.

    van der Klis, F., van den Hoorn, M. H., Blaauw, R., van Haveren, J. & van Es, D. S. Oxidative decarboxylation of unsaturated fatty acids. Eur. J. Lipid Sci. Technol. 113, 562–571 (2011).

  26. 26.

    Cassani, C., Bergonzini, G. & Wallentin, C. J. Photocatalytic decarboxylative reduction of carboxylic acids and its application in asymmetric synthesis. Org. Lett. 16, 4228–4231 (2014).

  27. 27.

    Griffin, J. D., Zeller, M. A. & Nicewicz, D. A. Hydrodecarboxylation of carboxylic and malonic acid derivatives via organic photoredox catalysis: substrate scope and mechanistic insight. J. Am. Chem. Soc. 137, 11340–11348 (2015).

  28. 28.

    Hamid, S. et al. Photocatalytic conversion of acetate into molecular hydrogen and hydrocarbons over Pt/TiO2: pH dependent formation of kolbe and Hofer–Moest products. J. Catal. 349, 128–135 (2017).

  29. 29.

    Al-Azri, Z. H. N. et al. The roles of metal co-catalysts and reaction media in photocatalytic hydrogen production: performance evaluation of M/TiO2 photocatalysts (M = Pd, Pt, Au) in different alcohol–water mixtures. J. Catal. 329, 355–367 (2015).

  30. 30.

    Panagiotopoulou, P. & Kondarides, D. I. Effects of promotion of TiO2 with alkaline earth metals on the chemisorptive properties and water–gas shift activity of supported platinum catalysts. Appl. Catal. B 101, 738–746 (2011).

  31. 31.

    Alexeev, O. S., Chin, S. Y., Engelhard, M. H., Ortiz-Soto, L. & Amiridis, M. D. Effects of reduction temperature and metal−support interactions on the catalytic activity of Pt/γ-Al2O3 and Pt/TiO2 for the oxidation of CO in the presence and absence of H2. J. Phys. Chem. B 109, 23430–23443 (2005).

  32. 32.

    Parsons, R. The rate of electrolytic hydrogen evolution and the heat of adsorption of hydrogen. Trans. Faraday Soc. 34, 1053–1063 (1958).

  33. 33.

    Heller, A., Aharon-Shalom, E., Bonner, W. A. & Miller, B. Hydrogen-evolving semiconductor photocathods: nature of the junction and function of the platinum group metal catalyst. J. Am. Chem. Soc. 104, 6942–6948 (1982).

  34. 34.

    Wen, B., Li, Y., Chen, C., Ma, W. & Zhao, J. An unexplored O2-involved pathway for the decarboxylation of saturated carboxylic acids by TiO2 photocatalysis: an isotopic probe study. Chem. Eur. J. 16, 11859–11866 (2010).

  35. 35.

    Panayotov, D. A. & Yates, J. T. Charge exchange between TiO2 and a polyfunctional chemisorbed molecule—the involvement of electrophilic groups. Chem. Phys. Lett. 399, 300–306 (2004).

  36. 36.

    Panayotov, D. A. & Yates, J. T. Spectroscopic detection of hydrogen atom spillover from Au nanoparticles supported on TiO2: use of conduction band electrons. J. Phys. Chem. C 111, 2959–2964 (2007).

  37. 37.

    Li, J. et al. Synergistic effect of surface and bulk single-electron-trapped oxygen vacancy of TiO2 in the photocatalytic reduction of CO2. Appl. Catal. B 206, 300–307 (2017).

  38. 38.

    Hurum, D. C., Agrios, A. G., Gray, K. A., Rajh, T. & Thurnauer, M. C. Explaining the enhanced photocatalytic activity of Degussa P25 mixed-phase TiO2 using EPR. J. Phys. Chem. B 107, 4545–4549 (2003).

  39. 39.

    Prins, R. Hydrogen spillover. Facts and fiction. Chem. Rev. 112, 2714–2738 (2012).

  40. 40.

    Schrauben, J. N. et al. Titanium and zinc oxide nanoparticles are proton-coupled electron transfer agents. Science 336, 1298–1301 (2012).

  41. 41.

    Karim, W. et al. Catalyst support effects on hydrogen spillover. Nature 541, 68–71 (2017).

  42. 42.

    Porosoff, M. D. & Chen, J. G. Trends in the catalytic reduction of CO2 by hydrogen over supported monometallic and bimetallic catalysts. J. Catal. 301, 30–37 (2013).

  43. 43.

    Chen, H.-Y. T., Tosoni, S. & Pacchioni, G. Hydrogen adsorption, dissociation, and spillover on Ru10 clusters supported on anatase TiO2 and tetragonal ZrO2 (101) surfaces. ACS Catal. 5, 5486–5495 (2015).

  44. 44.

    Wang, X., Wu, G., Guan, N. & Li, L. Supported Pd catalysts for solvent-free benzyl alcohol selective oxidation: effects of calcination pretreatments and reconstruction of Pd sites. Appl. Catal. B 115-116, 7–15 (2012).

  45. 45.

    Panagiotopoulou, P. & Kondarides, D. I. Effects of alkali promotion of TiO2 on the chemisorptive properties and water–gas shift activity of supported noble metal catalysts. J. Catal. 267, 57–66 (2009).

  46. 46.

    Weng, Z., Ni, X., Yang, D., Wang, J. & Chen, W. Novel photopolymerizations initiated by alkyl radicals generated from photocatalyzed decarboxylation of carboxylic acids over oxide semiconductor nanoparticles: extended photo-Kolbe reactions. J. Photochem. Photobiol., A 201, 151–156 (2009).

  47. 47.

    Liang, H. et al. Porous TiO2/Pt/TiO2 sandwich catalyst for highly selective semihydrogenation of alkyne to olefin. ACS Catal. 7, 6567–6572 (2017).

  48. 48.

    Pattanaik, B. P. & Misra, R. D. Effect of reaction pathway and operating parameters on the deoxygenation of vegetable oils to produce diesel range hydrocarbon fuels: a review. Renew. Sustain. Energy Rev. 73, 545–557 (2017).

  49. 49.

    Hill, J., Nelson, E., Tilman, D., Polasky, S. & Tiffany, D. Environmental, economic, and energetic costs and benefits of biodiesel and ethanol biofuels. Proc. Natl Acad. Sci. USA 103, 11206–11210 (2006).

  50. 50.

    Wang, Y. et al. Heterogeneous ceria catalyst with water-tolerant Lewis acidic sites for one-pot synthesis of 1,3-diols via prins condensation and hydrolysis reactions. J. Am. Chem. Soc. 135, 1506–1515 (2013).

  51. 51.

    Li, R., Han, H., Zhang, F., Wang, D. & Li, C. Highly efficient photocatalysts constructed by rational assembly of dual-cocatalysts separately on different facets of BiVO4. Energy Environ. Sci. 7, 1369–1376 (2014).

  52. 52.

    Zhang, Y., Zhang, N., Tang, Z.-R. & Xu, Y.-J. Identification of Bi2WO6 as a highly selective visible-light photocatalyst toward oxidation of glycerol to dihydroxyacetone in water. Chem. Sci. 4, 1820–1824 (2013).

  53. 53.

    Henderson, M., White, J. M., Uetsuka, H. & Onishi, H. Selectivity changes during organic photooxidation on TiO2: role of O2 pressure and organic coverage. J. Catal. 238, 153–164 (2006).

  54. 54.

    Jeništová, K. et al. Hydrodeoxygenation of stearic acid and tall oil fatty acids over Ni-alumina catalysts: influence of reaction parameters and kinetic modelling. Chem. Eng. J. 316, 401–409 (2017).

Download references


This work was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (grant no. XDB17000000) and the National Natural Science Foundation of China (grant nos. 21721004, 21690082, 21690084, 21690080, 21711530020).

Author information




Z.H. designed and conducted most of the experiments, and wrote the manuscript. Z.Z. carried out the life-cycle assessment and wrote the manuscript. C.Z. contributed to experiment design and manuscript revisions. J.L. performed the DFT study. H.L., N.L. and J.Z. contributed to product analysis, photoreactor design and mechanism investigation. General guidance, project directing and manuscript revisions were done by F.W.

Corresponding author

Correspondence to Feng Wang.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary Methods, Discussion, Figs. 1–27, Tables 1–9 and references.

Supplementary Data

Atomic coordinates of the optimized computational models.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Huang, Z., Zhao, Z., Zhang, C. et al. Enhanced photocatalytic alkane production from fatty acid decarboxylation via inhibition of radical oligomerization. Nat Catal 3, 170–178 (2020). https://doi.org/10.1038/s41929-020-0423-3

Download citation

Further reading