SAPO-34 crystallized using novel pyridinium template as highly active catalyst for synthesis of ethyl levulinate biofuel

Direct evidence of time-dependent crystallization evolution of SAPO-34 and SAPO-20 zeolites directed by trimethylbenzylammonium hydroxide for microwave-assisted ethanolysis of furfuryl alcohol

“…The signals at 734 and 642 cm −1 correspond to the cha and d6r composite building units (CBUs) of SAPO-34, while its bending vibrations of PO 4 , AlO 4 and SiO 4 can be found at 570, 521 and 483 cm −1 , respectively. 16,40 These IR bands become more intense and slightly left-shifted after 24 h indicating the change in the P–O–T bond length and angle (T = Si or Al) and an increase of the SAPO-34 composition in the solid, in accordance with the XRD data (Fig. 1c and 2c).…”

“…[10][11][12] SAPO-34 (CHA topology) is one of the most important industrial zeolites used in gas separation, 13 methanol-to-olefins (MTO), 14 aromatization of methanol 15 and other catalytic reactions. [16][17][18] The vast applications of SAPO-34 can be related to its excellent porous properties that are formed by a threedimensional channel system with a pore opening of 3.80 Â 3.80 Å 2 , and a large accessible CHA cage with 9.4 Å diameter. 19 Meanwhile, other SAPO zeolites, such as SAPO-20 (SOD topology), are small pore zeolites with a pore opening of 2.53 Â 2.53 Å 2 , which are useful in selective removal of nitrogen oxides from exhaust gases, and separation of hydrogen gas from gas mixtures.…”

Levulinic Acid Esterification with n-Butanol over a Preyssler Catalyst in a Microwave-Assisted Batch Reactor: A Kinetic Study

“…Effect of the Microwaves. The increase of the reaction rate is one of the main features of the use of microwaves for the esterification route of different fatty acids as has been reported for the production of alkyl levulinates as fuel additives, using different heterogeneous catalysts such as silicoaluminophosphate (SAPO-34), 73 recyclable sulfated amorphous nanosilica, 74 and tin modified silicotungstic acid (STA)/Ta 2 O 5 75 but also calix [4]arene as an organocatalyst. 76 This increase is directly related to a decrease in the required reaction time to achieve a specific yield of the levulinate.…”