3-Bromopyridine-Heterogenized Phosphotungstic Acid for Efficient Trimerization of Biomass-Derived 5-Hydroxymethylfurfural with 2-Methylfuran to C₂₁ Fuel Precursor

Table 2

Catalytic results for the synthesis of MMBM from 2-MF and HMF over different catalysts.

Catalyst	Yield (MMBM, %)	Conversion (2-MF, %)
HPW	32.9	81.7
HPyPW	0.1	21.1
3-BrPyPW	57.1	82.0
Amberlyst-15	12.3	37.9
Nafion-117	25.8	76.4

Reaction conditions: 3 mmol 2-MF, 1 mmol HMF, 20 mg catalyst, 2 mL solvent, 100°C, and 8 h.