High Structure Sensitivity of Vapor-Phase Furfural Decarbonylation/Hydrogenation Reaction Network as a Function of Size and Shape of Pt Nanoparticles

Abstract

Vapor-phase transformations of furfural in H(2) over a series of Pt nanoparticles (NPs) with various particle sizes (1.5-7.1 nm size range) and shapes (rounded, cubes, octahedra) encapsulated in poly(vinylpyrrolidone) (PVP) and dispersed on MCF-17 mesoporous silica were investigated at ambient pressure in the 443-513 K temperature range. Furan and furfuryl alcohol (FFA) were two primary products as a result of furfural decarbonylation and hydrogenation reactions, respectively. Under conditions of the study both reactions exhibited structure sensitivity evidenced by changes in product selectivities, turnover rates (TORs), and apparent activation energies (E(A)'s) with Pt particle size and shape. For instance, upon an increase in Pt particle size from 1.5 to 7.1 nm, the selectivity toward FFA increases from 1% to 66%, the TOR of FFA production increases from 1 × 10(-3) s(-1) to 7.6 × 10(-2) s(-1), and E(A) decreases from 104 kJ mol(-1) to 15 kJ mol(-1) (9.3 kPa furfural, 93 kPa H(2), 473 K). Conversely, under the same experimental conditions the decarbonylation reaction path is enhanced over smaller nanoparticles. The smallest NPs (1.5 nm) produced the highest selectivity (96%) and highest TOR values (8.8 × 10(-2) s(-1)) toward furan formation. The E(A) values for decarbonylation (∼62 kJ mol(-1)) was Pt particle size independent. Furan was further converted to propylene via a decarbonylation reaction, but also to dihydrofuran, tetrahydrofuran, and n-butanol in secondary reactions. Furfuryl alcohol was converted to mostly to 2-methylfuran.

Conversion of furan derivatives for preparation of biofuels over Ni–Cu/C catalyst

“…20 Particularly, FU is regarded as one of the top 10 biorefinery building chemicals (Bozell and Petersen, 2010), since FU can be widely used to produce fuels and chemicals such as furan, furfural alcohol (FOL), 2-methylfuran (2-MF), tetrahydrofuran (THF), and cyclopentanone. as shown in Scheme 1 (Pushkarev et al, 2012;Bohre et al, 2015). Among the products, 2-MF can be used as a fuel additive with high research octane number (103 > 97 of gasoline) and adequate energy density (28.5 MJ/L > 25 21.0 MJ/L of ethanol) (Bohre et al, 2015).…”

“…The product distribution remarkably changed with varied temperatures. Furan from decarbonylation of FU was more generated at higher temperatures since it is an endothermic process (Pushkarev et al, 2012). THF and butanol, respectively, derived 60 from deep hydrogenation and ring-opening conversion of furan, were more generated at high temperatures as well, making the product distribution complex.…”

Nanocatalysis I: Synthesis of Metal and Bimetallic Nanoparticles and Porous Oxides and Their Catalytic Reaction Studies

“…The size of nanoparticles influences not only the reaction rate but also the product selectivity. Many hydrogenation reactions of small molecules including pyrrole [53], furan [54], crotonaldehyde [55], butadiene [56], furfural [57], methylcyclopentane [58], cyclohexene [59], and nhexane [60] have been proven to change their selectivity by Pt nanoparticle size or shape. For example, in 1,3-butadiene hydrogenation, 0.9 and 1.8 nm Pt nanoparticles increased the production of n-butane by full hydrogenation, whereas 4.6 and 6.7 nm Pt catalysts favored 1-butene by partial hydrogenation [56].…”

“…The product selectivity was greatly changed as well in furfural hydrogenation. Pushkarev et al investigated the change of catalytic activity and selectivity in furfural hydrogenation by using supported Pt nanoparticles with different sizes and shapes [57]. For example, as the Pt size was increased from 1.5 to 7.1 nm, the selectivity toward furfuryl alcohol increased from 1 to 66 % and turnover rates of the furfuryl alcohol production remarkably increased from 1 9 10 -3 to 7.6 9 10 -2 s -1 , while activation energies decreased gradually.…”

Hydroisomerization of n-hexadecane: remarkable selectivity of mesoporous silica post-synthetically modified with aluminum

“…MCF-17 is another amorphous silica with interconnected spherical pores with average diameter of 26.5 nm. 34,35 SPP is a crystalline silica compound with hierarchical pore structure. 36 It contains both mesopores with average pore diameter of 6.5 nm and a network of ~0.5 nm micropores with MFI microstructure.…”