Zhi Zheng,Jun Wang,Yi Wei,Xuejun Liu,Fengwen Yu,Jianbing Ji
La-Fe modified Si-MCM-41 (La-Fe/Si-MCM-41) catalysts were prepared by the wet impregnation method and used in catalytic cracking of soybean oil (CCS) for biofuel production. The catalysts were characterized by BET, XRD, XPS, Py-FTIR and CO 2 -TPD. The results showed that the aromatics content increased with the increase in B/L value, while the content of oxygenated compounds decreased, indicating that Brönsted acid sites were the major active sites for deoxygenation and aromatization reactions. Compared with Si-MCM-41, the Brönsted acidity of LFM-6 sharply decreased from 22.49 to 5.86 μmol g −1 . Accordingly, the aromatics content was reduced from 37.51 wt.% to 14.52 wt.% which was lower than the limitation (15 wt.%) according to the global environmental legislation. However, for the LFM-6 catalyst, the excessive loss of Brönsted acid sites and sharp decrease in BET surface area and pore volume led to the decrease in deoxygenation. As a result, the fatty acids content increased from 2.71 wt.% to 16.67 wt.% and the acid value reached 35.20 mgKOH g −1 . When the La-Fe loading increased to 15 wt.%, part of fatty acids were converted into ketones by the active sites on Fe 2 O 3 /La 2 O 3 and strong Lewis acid sites on catalysts. Besides, the new weak Lewis acid and basic sites on Fe 2 O 3 /La 2 O 3 exhibited the synergistic effect on promoting the generation of alkenes. The CaO/LFM-6 composite catalysts prepared by the mechanical mixing of LFM-6 and CaO were used in CCS to reduce the acid value of biofuel. LFM-6-C-3 was proved to be an effective catalyst for CCS to produce biofuel with low aromatics (12.31 wt.%) and fatty acids (2.76 wt.%) content.
Introduction of the sulfonic acid group into H-β zeolite to prepare β-SO 3 H bifunctional catalysts for the efficient synthesis of 5-hydroxymethylfurfural (HMF) from cellulose . Catalysts characterization, such as XRD, ICP-OES, SEM (Mapping), FTIR, XPS , N 2 adsorption-desorption isotherm, NH 3 -TPD, Py-FTIR demonstrate the sulfonic acid group was successfully grafted onto the β zeolite. A superior HMF yield (59.4 %) and cellulose conversion (89.4 %) was obtained in the H 2 O(NaCl)/THF biphasic system under 200 °C for 3 h with β-SO 3 H(3) zeolite as catalyst. More valuable, β-SO 3 H(3) zeolite converts other sugars and obtains ideal HMF yield, including fructose (95.5 %), glucose (86.5 %), sucrose (76.8 %), maltose (71.5 %), cellobiose (67.0 %), starch (68.1 %), glucan (64.4 %) and also converts plant material (25.1 % for moso bamboo and 18.7 % for wheat straw) with great HMF yield. β-SO 3 H(3) zeolite catalyst keeps an appreciable recyclability after 5 cycles. Moreover, in the presence of β-SO 3 H(3) zeolite catalyst, the by-products during the production of HMF from cellulose were detected, and the possible conversion pathway of cellulose to HMF was proposed. The β-SO 3 H bifunctional catalyst has excellent potential for the biorefinery of high value platform compound from carbohydrates.