Maseko Ncamisile Nondumiso, Enke Dirk, Owolawi Pius Adewale, Iwarere Samuel Ayodele, Oluwafemi Oluwatobi Samuel, Pocock Jonathan
Discipline of Chemical Engineering, University of KwaZulu-Natal, 238 Mazisi Kunene Road, Glenwood, Durban 4041, South Africa.
Institute of Chemical Technology, Universität Leipzig, Linnéstr. 3, 04103 Leipzig, Germany.
Gels. 2025 Feb 20;11(3):153. doi: 10.3390/gels11030153.
Biodiesel was produced via transesterification of canola oil in the presence of a silica xerogel catalyst with deposited gold nanoparticles. The silica-gold catalyst was produced in situ, where gold metal was added to a sodium silicate solution; subsequently, gold nanoparticles were synthesised within the solution. The sodium silicate-gold nanoparticles solution was then turned into a silica-gold gel at pH 8.7 and later dried to form silica-gold nanoparticles xerogel. The produced silica-gold nanoparticles xerogel was characterised by X-ray diffraction (XRD), X-ray fluorescence (XRF), transition electron microscopy (TEM), and nitrogen physisorption. The gel had a silica content of 91.6 wt% and a sodium content of 6.4 wt%, with the added gold content being 99.5% retained. The biodiesel produced in the presence of silica-gold nanoparticles xerogel was characterised by gas chromatography-mass spectroscopy (GC-MS) and its physical properties, such as density, kinematic viscosity, flash point, pour point, and cloud point, were also determined. The silica-gold nanoparticles xerogel catalyst remained solid throughout its usage without leaching into the reaction medium. The produced biodiesel contained mostly monounsaturated fatty acid methyl esters and had a yield of 99.2% at optimum reaction conditions.
生物柴油是在含有沉积金纳米颗粒的硅胶干凝胶催化剂存在下，通过菜籽油的酯交换反应生产的。硅胶-金催化剂是原位制备的，将金金属添加到硅酸钠溶液中；随后，在溶液中合成金纳米颗粒。然后将硅酸钠-金纳米颗粒溶液在pH 8.7条件下转变为硅胶-金凝胶，随后干燥形成硅胶-金纳米颗粒干凝胶。通过X射线衍射（XRD）、X射线荧光（XRF）、透射电子显微镜（TEM）和氮物理吸附对制备的硅胶-金纳米颗粒干凝胶进行了表征。该凝胶的二氧化硅含量为91.6 wt%，钠含量为6.4 wt%，添加的金含量保留率为99.5%。通过气相色谱-质谱联用（GC-MS）对在硅胶-金纳米颗粒干凝胶存在下生产的生物柴油进行了表征，并测定了其密度、运动粘度、闪点、倾点和浊点等物理性质。硅胶-金纳米颗粒干凝胶催化剂在整个使用过程中保持固态，没有渗入反应介质。所生产的生物柴油主要含有单不饱和脂肪酸甲酯，在最佳反应条件下产率为99.2%。
