Heteropolyacid catalysts for Diels-Alder cycloaddition of 2,5-dimethylfuran and ethylene to renewable p -xylene

Comparative Study of Different Acidic Surface Structures in Solid Catalysts Applied for the Isobutene Dimerization Reaction

“…This was expected since HSAG 100 is a graphitic support that barely holds any acid site; hence the acidity of this catalyst is given mostly by the STA which is in a 15 wt.%. However, it is worth highlighting that the heteropolyacid also retains its acidity despite being supported, and this suggests a weak interaction between STA and the graphite as observed previously in silica-supported systems [35]. In contrast, the other tested catalysts are either bulk catalysts, A15 and ZS, or NiO 5 wt.% supported on alumina, so the total acidity is obviously higher as it emerges from the structure and the surface groups themselves.…”

Dynamic Trapping as a Selective Route to Renewable Phthalide from Biomass‐Derived Furfuryl Alcohol

“…[2] One route to aromatics that has received significant attention of late combines a Diels-Alder (DA) reaction of biomassderived furanics with a second dehydration (aromatisation) step (Scheme 1 A). [1] Notable examples include the synthesis of: p-xylene from dimethylfuran and ethylene, [3][4][5][6][7][8][9][10][11][12][13][14] acrylic acid [15,16] or acrolein; [17] benzene/toluene from furan and ethylene/propylene; [18] and (substituted) phthalic anhydride from (substituted) furan and maleic anhydride. [19][20][21] In general, there are two key considerations that determine how successful these reactions are: 1) the kinetic and thermodynamic efficiency of the DA reaction and 2) the ease with which the resulting DA cycloadduct can be aromatised.…”

p-Xylene from 2,5-dimethylfuran and acrylic acid using zeolite in a continuous flow system

“…34 Also, heteropolyacids and sulfonic acids supported on SiO 2 showed a high DMF conversion (94%) and pXL selectivity (85%), here due to enhanced Brønsted acid sites at 523 K, 2.0 MPa and 6 h of reaction time. 35,36 From the above investigations, high acid site density combined with high surface area seems to be essential for catalysts used in the Diels-Alder cycloaddition of DMF/ethylene followed by dehydration of the intermediate product. Alternatively, several trials were made for the synthesis of aromatics by Diels-Alder cycloaddition using furans and ethanol (as in situ ethylene source) over zeolite as catalysts in a batch system.…”

“…Alternatively, several trials were made for the synthesis of aromatics by Diels-Alder cycloaddition using furans and ethanol (as in situ ethylene source) over zeolite as catalysts in a batch system. [36][37][38][39] However, this approach requires high reaction temperatures to dehydrate ethanol to ethylene and leads to high amounts of by-products. An alternative route for the sustainable production of aromatics from furanics was proposed by replacing ethylene with different dienophiles such as acrylic acid (AA) or maleic anhydride (MA).…”