Bifunctional 1,2,4-Triazole/12-Tungstophosphoric Acid Composite Nanoparticles for Biodiesel Production

Gicheon Lee; Chanmin Lee; Hyungjin Kim; Yukwon Jeon; Yong-Gun Shul; Jinwon Park

doi:10.3390/nano12224022

Bifunctional 1,2,4-Triazole/12-Tungstophosphoric Acid Composite Nanoparticles for Biodiesel Production

Nanomaterials (Basel). 2022 Nov 16;12(22):4022. doi: 10.3390/nano12224022.

Authors

Gicheon Lee^{1

2}, Chanmin Lee², Hyungjin Kim³, Yukwon Jeon³, Yong-Gun Shul¹, Jinwon Park¹

Affiliations

¹ Department of Chemical and Biomolecular Engineering, Yonsei University, Yonsei-ro 50, Seodaemun-gu, Seoul 120-749, Republic of Korea.
² Green and Sustainable Materials R&D Department, Korea Institute of Industrial Technology, 89 Yangdaegiro-gil, Ipjan-myeon, Seobuk-gu, Cheonan-si 31056, Chungcheongnam-do, Republic of Korea.
³ Department of Environmental and Energy Engineering, Yonsei University, 1 Yonseidae-gil, Wonju 26493, Republic of Korea.

Abstract

Here, a composite nanoparticle with an acid-base bifunctional structure has been reported for the transesterification of rapeseed oil to produce biodiesel. Triazole-PWA (PWA = 12-tungstophosphoric acid) composite materials with a hexahedral structure are produced using the precipitation method, showing the average particle diameters of 200-800 nm. XPS and FT-IR analyses indicate well-defined chemical bonding of triazole moieties to the PWA. The functionalization and immobilization of PWAs are investigated due to strong interactions with triazole, which significantly improves the thermal stability and even surface area of the heteropoly acid. Furthermore, various ratios of triazole and PWAs are examined using NH₃-TPD and CO₂-TPD to optimize the bi-functionality of acidity and basicity. The prepared nanomaterials are evaluated during the transesterification of rapeseed oil with methanol to analyze the effect of triazole addition to PWAs according to the different ratios. Overall, the bifunctional triazole-PWA composite nanoparticles exhibit higher fatty acid methyl ester (FAME) conversions than pure PWA nanoparticles. The optimized catalyst with a triazole:PWA ratio of 6:1 exhibits the best FAME-conversion performance due to its relatively large surface area, balance of acidity, and strong basicity from the well-designed chemical nano-structure.

Keywords: acid–base bifunctional composite; biodiesel; heteropoly acid; transesterification; triazole.

Grants and funding

This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT) (no. 2020R1F1A1073201). This work was supported by the Korea Institute of Industrial Technology through the “Development of inside solutions module to reduce harmful environmental factors in the atmosphere (EH-22-0010)”.