Highly efficient acrylic acid production from formaldehyde and acetic acid over the NASICON-type catalyst

The condensation of formaldehyde and acetic acid to acrylic acid (AA) is considered as one of the important routes for the clean and high value utilization of coal-based methanol derivatives. Herein, we successfully synthesized environment-friendly NASICON catalysts using Ti(SO₄)₂ as the titanium source. With guaranteed high selectivity (∼78%), the space time yield of AA + MA (methyl acrylate) can be up to 123.9 μmol g^-1 min^-1, far higher than the results reported previously. Based on the characterizations, it is demonstrated that the modulation of the acidic and basic properties (including distribution, ratio of B/L, etc.) led by the specific elemental and hybrid TiP₂O₇ phase plays crucial roles in catalyst supremacy.