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

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

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

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

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

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

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. Heciak, A., Morawski, A. W., Grzmil, B. & Mozia, S. Cu-modified TiO 2 photocatalysts for decomposition of acetic acid with simultaneous formation of C1–C3 hydrocarbons and hydrogen. Appl. Catal. B 140-141, 108–114 (2013).

18. Betts, L. M., Dappozze, F. & Guillard, C. Understanding the photocatalytic degradation by P25 TiO 2 of acetic acid and propionic aicd in the pursuit of alkane production. Appl. Catal. A 554, 35–43 (2018).

19. Ngo, S. et al. Kinetics and mechanism of the photocatalytic degradation of acetic acid in absence or presence of O 2 . J. Photochem. Photobiol. A 339, 80–88 (2017).

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

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. 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. 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. 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. 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. 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. 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. Hamid, S. et al. Photocatalytic conversion of acetate into molecular hydrogen and hydrocarbons over Pt/TiO 2 : pH dependent formation of kolbe and Hofer–Moest products. J. Catal. 349, 128–135 (2017).

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/TiO 2 photocatalysts (M = Pd, Pt, Au) in different alcohol–water mixtures. J. Catal. 329, 355–367 (2015).

30. Panagiotopoulou, P. & Kondarides, D. I. Effects of promotion of TiO 2 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. 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-Al 2 O 3 and Pt/TiO 2 for the oxidation of CO in the presence and absence of H 2 . J. Phys. Chem. B 109, 23430–23443 (2005).

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

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. Wen, B., Li, Y., Chen, C., Ma, W. & Zhao, J. An unexplored O 2 -involved pathway for the decarboxylation of saturated carboxylic acids by TiO 2 photocatalysis: an isotopic probe study. Chem. Eur. J. 16, 11859–11866 (2010).

35. Panayotov, D. A. & Yates, J. T. Charge exchange between TiO 2 and a polyfunctional chemisorbed molecule—the involvement of electrophilic groups. Chem. Phys. Lett. 399, 300–306 (2004).

36. Panayotov, D. A. & Yates, J. T. Spectroscopic detection of hydrogen atom spillover from Au nanoparticles supported on TiO 2 : use of conduction band electrons. J. Phys. Chem. C 111, 2959–2964 (2007).

37. Li, J. et al. Synergistic effect of surface and bulk single-electron-trapped oxygen vacancy of TiO 2 in the photocatalytic reduction of CO 2 . Appl. Catal. B 206, 300–307 (2017).

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 TiO 2 using EPR. J. Phys. Chem. B 107, 4545–4549 (2003).

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

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

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

42. Porosoff, M. D. & Chen, J. G. Trends in the catalytic reduction of CO 2 by hydrogen over supported monometallic and bimetallic catalysts. J. Catal. 301, 30–37 (2013).

43. Chen, H.-Y. T., Tosoni, S. & Pacchioni, G. Hydrogen adsorption, dissociation, and spillover on Ru 10 clusters supported on anatase TiO 2 and tetragonal ZrO 2 (101) surfaces. ACS Catal. 5, 5486–5495 (2015).

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. Panagiotopoulou, P. & Kondarides, D. I. Effects of alkali promotion of TiO 2 on the chemisorptive properties and water–gas shift activity of supported noble metal catalysts. J. Catal. 267, 57–66 (2009).

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. Liang, H. et al. Porous TiO 2 /Pt/TiO 2 sandwich catalyst for highly selective semihydrogenation of alkyne to olefin. ACS Catal. 7, 6567–6572 (2017).

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. 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. 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. 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 BiVO 4 . Energy Environ. Sci. 7, 1369–1376 (2014).

52. Zhang, Y., Zhang, N., Tang, Z.-R. & Xu, Y.-J. Identification of Bi 2 WO 6 as a highly selective visible-light photocatalyst toward oxidation of glycerol to dihydroxyacetone in water. Chem. Sci. 4, 1820–1824 (2013).

53. Henderson, M., White, J. M., Uetsuka, H. & Onishi, H. Selectivity changes during organic photooxidation on TiO 2 : role of O 2 pressure and organic coverage. J. Catal. 238, 153–164 (2006).