| 초록 |
Pt catalysts supported on crystalline Nb2O5•xH2O, and amorphous SiO2, Al2O3 and Nb2O5 aerogels were tested for their activity in the aqueous phase hydrodeoxygenation (APHDO) of 1-PrOH at 230 °C and 35 bar. The catalysts supported on amorphous SiO2, Al2O3, Nb2O5 and crystalline niobic acid calcined at 500 °C showed low activities or deactivation. Under the APHDO condition, these supports experienced a structure transformation to crystalline quartz, boehmite and niobia TT phase. Thus, Pt/Nb2O5–Al2O3 and Pt/Nb2O5–SiO2 aerogels were prepared and tested; however, the former catalyst experienced the crystallization into TT–Nb2O5 and boehmite under the reaction condition. In contrast, Pt/Nb2O5–SiO2 aerogels with different Nb/(Nb+Si) ratios were found to retain X-ray amorphous and porous structure. Also, their acid site densities were negligibly changed during the reaction. In terms of the catalytic performance, Pt/Nb2O5–SiO2 aerogel catalysts exhibited the similar conversion around 50% up to 24 h and the molar propane/ethane ratio increased to about 1.0 with the acid site density. |
