SELECTIVE CATALYTIC TRANSFER HYDROGENATION OF FURFURALDEHYDE TO FURFURYL ALCOHOL OVER PT/AL2O3

• Main Author: FAUZIAH ( NIM : 20514061 ), RATIH
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/23845
• Institution: Institut Teknologi Bandung

<br /> <br /> <br /> Transfer hydrogenation of furfural to furfuryl alcohol (FOL) was catalysed by series of Pt/Al2O3 catalysts using isopropanol (IPA) as hydrogen donor. The catalysts used in this research are 1% Pt/Al2O3 and 5% Pt/Al2O3 (brown and black). All the catalysts were characterized using XRD and TEM. XRD patterns of the catalyst confirmed that Pt were impregnated on &#945;-Al2O3, with characteristic 2&#952; of Pt (111), (200) and (220) were detected at 39.8°, 46.5°, and 67.8° respectively. TEM images showed that Pt particle size on 1%Pt/Al2O3, 5% Pt/Al2O3 (brown) and 5% Pt/Al2O3 (black) were 3 nm, 2.5 nm and 4 nm, respectively. The catalytic tests were run under different mole ratio of reactant/catalyst (1560 and 390 with 1% Pt/Al2O3; and 312 <br /> & 78 with 5% Pt/Al2O3) at varied temperature (100 °C–180 °C). The best conversion of furfural (85%) and the FOL selectivity (100%) were obtained with <br /> <br /> <br /> 1% Pt/Al2O3 catalyst (FAL/Cat (mmol) = 390) at 160 °C in 4 hours. Higher Pt concentration in 5% Pt/Al2O3 (brown and black) catalysts reduced the FOL selectivity because of THFA and other unknown product formation. Transfer hydrogenation of FAL over 5% Pt/Al2O3 (brown) and 5% Pt/Al2O3 (black) resulted in different product selectivity. At the same condition (140 °C, 4h, FAL/Cat (mmol) <br /> <br /> <br /> = 78), hydrogenation over 5% Pt/Al2O3 (brown) produced only FOL with >99% selectivity towards FOL. On the other side, hydrogenation over 5% Pt/Al2O3 <br /> <br /> <br /> produced FOL and other unknown product (Unknown). Transfer hydrogenation of FAL over 1% Pt/Al2O3 (FAL/Cat (mmol) = 390) were conducted at 180 °C for 20 h, and resulted in formation of FOL, THFA and Unknown. In such a case, the selectivity decreased because of longer contact time between reactant and catalyst. Previous report explained that hydrogenation products depend on FAL adsorption modes on the catalyst. The vertical mode of FAL adsorption gave FOL product. Hydrogenation of FAL over Pt catalyst is structure and shape sensitive. Pt (111) plane facilitates more hydrogenation than decarboylation reaction. The study conducted in this research revealed that isopropanol worked as hydrogen donor without a hydride formation on Pt/Al2O3 surface, the results shows no acetone formation in 1H-NMR spectra. Transfer hydrogenation of furfural over 1% Pt/Al2O3 was predicted to be the first order towards furfural, with an activation energy (Ea) of 70 kJmol-1. <br />