Deposition of NiO Nanoparticles on Nanosized Zeolite NaY for Production of Biofuel via Hydrogen-Free Deoxygenation

Abstract

Nickel-based catalysts play an important role in the hydrogen-free deoxygenation for the production of biofuel. The yield and quality of the biofuel are critically affected by the physicochemical properties of NiO supported on nanosized zeolite Y (Y65, crystal size of 65 nm). Therefore, 10 wt% NiO supported on Y65 synthesized by using impregnation (IM) and deposition–precipitation (DP) methods were investigated. It was found that preparation methods have a significant effect on the deoxygenation of triolein. The initial rate of the DP method (14.8 goil·h−1) was 1.5 times higher than that of the IM method (9.6 goil·h−1). The DP-Y65 showed the best deoxygenation performance with a 80.0% conversion and a diesel selectivity of 93.7% at 380 °C within 1 h. The outstanding performance from the DP method was due to the smaller NiO particle size (3.57 ± 0.40 nm), high accessibility (H.F value of 0.084), and a higher Brönsted to Lewis acidity (B/L) ratio (0.29), which has improved the accessibility and deoxygenation ability of the catalyst. The NH4+ released from the decomposition of the urea during the DP process increased the B/L ratio of zeolite NaY. As a result, the pretreatment to convert Na-zeolite to H-zeolite in a conventional zeolite synthesis can be avoided. In this regard, the DP method offers a one-pot synthesis to produce smaller NiO-supported nanosized zeolite NaY with a high B/L ratio, and it managed to produce a higher yield with selectivity towards green diesel via deoxygenation under a hydrogen-free condition.

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

“…Furthermore, the Non-local Density Functional Theory (NLDFT) method also reveals that SAPO-34 has a larger average pore size (3.26 nm) due to its primary micro-and textural mesoporosities. 51 Meanwhile, SAPO-20 shows a large average pore size in the macropore range (72.9 nm), whereby its micropores (0.253 Â 0.253 nm 2 ) are inaccessible and unmeasurable by bulkier N 2 probe molecules. 52 The surface acidity and molecular accessibility of both zeolites are further supported by a TPD-NH 3 study, viz.…”

Effect of Synthesis Methods on the Catalytic Reforming of Kerosene

“…According to this mechanism, both Lewis and Brønsted acid sites advance the reforming process. 4 Metals play the role of Lewis acid sites, and the supports provide the Brønsted acid sites. Therefore, the incorporation of the metals into the catalysts is needed to enhance the chemicals in these types of processes.…”

“…3 While most bifunctional catalysts in recent studies have been prepared by one preparation method, different preparation methods of catalysts tend to influence their behaviour during the process as well as the properties of the produced fuels. 4,5 Various parameters such as pH, reaction temperature, reaction time, and type of solvent are important in obtaining a ceramic powder with the desired shape and size. 6 Therefore, synthetic strategies of catalysts are important in a chemical process, and catalyst preparation is known as the main path to a desired activity and selectivity.…”

“…9,10 Each preparation method has advantages and disadvantages. 4 For instance, depositionprecipitation and sol-gel methods are among the most common techniques applied to synthesize the nanoparticles. Proper metal dispersion is achievable by the sol-gel method.…”