SINTESIS KARBON MESOPORI DARI FRUKTOSA DENGAN MENGGUNAKAN AKTIVATOR SENG BOROSILIKAT; SYNTHESIS OF MESOPOROUS CARBON FROM FRUCTOSE USING ZINC BOROSILICATE

SETIANINGSIH,TUTIK, Indriana Kartini

2016 | Tesis | FMIPA

Some methods of pore enlargements have been applied in synthesis of carbon, involving various chemical activators and pore templates. ZnCl2 is a chemical activator which can form pore at low temperature (450 oC), but with pore size (Dmax) of 7 nm with borosilicate template. In other side, the mesoporous carbon has been synthesized from sucrose and resulted in pore size (Dmax) larger than 7 nm but at high temperature (900 oC). Purpose of the research is to synthesize mesoporous carbon with pore uniformity > 7 nm at low temperature using zinc borosilicate (ZBS) activator. To achieve the purpose. synthesis was conducted at various temperature (350, 450, 550, 650, and 750 oC) and various ZBS composition, including at various mass ratio of SiO2/fructose (0; 1.0; 2.0; 3.0; and 4.0 g g-1), mass ratio of H3BO3/fructose (0; 0.6; 1.2; 1.8; 2.4; and 3.7 g g-1), and mass ratio of ZnCl2/fructose (0; 0.5; 1.0; 1.5; 2.0; and 3.0 g g-1). The synthesis involved 3 steps, including caramelization process (at 100 oC for 4 h under stirring, then continued at 130 oC in the oven), carbonization (at 2 h under nitrogen gas stream), and washing process using HF 48% solution, HCl 1M solution, dan distillated water. Some characterizations of the products were performed, including pore characterization with nitrogen adsorption-desorption method, surface functional group with FTIR spectrophotometry, crystal structure characterization with X-ray diffraction method, and morphology of surface with TEM and SEM. Result of the research shows that all carbon products have mesoporous characteristics. Study of synthesis parameters showed that there was improvement of mesoporous carbon from carbonization temperature of 350 to 450 oC, mass ratio of SiO2/fructose = 2.0 g g-1, mass ratio of H3BO3/fructose = 1.24 g g-1, and mass ratio of ZnCl2/fructose = 1.0 g g-1, then decrease again. The optimum synthesis conditions were carbonization temperature of 450 oC with mass ratio of SiO2/fructose = 2.0 g g-1, H3BO3/fructose = 1.24 g g-1; and ZnCl2/fructose = 1.0 g g-1. The carbon characteristics achieved by this research were pore morphology of 3 dimension with Dmax of 30 nm (ads) and 18 nm (des), Vmeso of 1.68 cm3 g-1 (ads) and 2.88 cm3 g-1 (des), mesoporosity of 76.7 %(v) and macroporosity of 19.0%(v), surface functional groups of -OH, C=O, and C-O, and mixture of amorph and graphite structures, with graphitization degree of 33.2%. ZBS contains zinc borate (Zn3B2O6) and zinc silicate (Zn2SiO4) crystals, based on characterization using X-ray diffraction method. Zinc borate has large mesopore size controller of the carbon.

Kata Kunci : mesoporous carbon, fructose, ZBS