Aldol condensation of acetic acid with formaldehyde to acrylic acid over SiO2-, SBA-15-, and HZSM-5-supported V-P-O catalysts

• Aldol condensation of acetic acid with HCHO was catalyzed by supported VPO catalysts.
• Support type and P/V ratio obviously affected the acid–base properties of catalyst.
• Both acid and base sites played important roles for the aldol condensation reaction.
• VPO/SBA-15 catalyst with high basicity and acidity exhibited high catalytic activity.

Aldol condensation of acetic acid with formaldehyde to acrylic acid was catalyzed by the SiO2-, SBA-15-, and HZSM-5-supported vanadium phosphorous oxide (V-P-O) catalysts prepared by the incipient wetness impregnation. The supports obviously increased the surface areas and changed the acid–base properties of the as-prepared catalysts. V-P-O/SBA-15 catalysts with high acid and alkali quantities exhibited high catalytic activities for the aldol condensation of acetic acid with formaldehyde to acrylic acid. When the V-P-O/SBA-15 catalyst with the P/V mole ratio of 2.0:1 catalyzed the reaction at 330–370 °C, the acrylic acid selectivities were 90.8–70.2% at the formaldehyde conversions of 14.3–68.7%.

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