2,3-Butanediol dehydration catalyzed by silica-supported alkali phosphates

[Display omitted] •Alkali phosphates are active in 2,3-butanediol dehydration realized via four parallel pathways.•Selectivity to the specific pathway is tuned by the nature of alkali cation and M/P ratio.•Stronger acid-base pairs appear as soon as alkali cations are added to phosphate.•Isolated Brønsted acid centers are responsible for the rearrangement pathway.•Stronger acid-base pairs are responsible for the elimination pathway. Characterization of acid-base centers and catalytic dehydration of 2,3-butanediol (BDO) was performed over a wide range of silica-supported alkali phosphates (M_P/SiO2; M = Na, K, Cs; M:P = 0.5–3 mol:mol). Selectivity to 1,3-butadiene (BD) and 3-butene-2-ol (3B2OL) formed by elimination correlates with the densities of conjugated acid-base pairs and increases in the order Na