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The role of the crystalline phase of Mo3VO x in the catalytic oxidation of allyl alcohol over four kinds of crystalline (orthorhombic, trigonal, tetragonal, amorphous) Mo3VO x catalysts was investigated to determine the active sites for the reactions. Tetragonal Mo3VO x was found less active for the formation of acrylic acid from allyl alcohol, although acrolein was obtained selectively at higher temperature. For orthorhombic and trigonal Mo3VO x catalyst, allyl alcohol converted to acrolein and propanal competitively at the mouth of the heptagonal channel over the a- b plane of the rod-type crystalline particles, and these aldehydes were oxidized consecutively to acrylic acid. Acrylic acid was formed effectively at increased reaction temperature over orthorhombic, trigonal and amorphous Mo3VO x catalysts, and the maximum yields of acrylic acid were 73 % for the orthorhombic Mo3VO x catalyst and 72 % for the trigonal Mo3VO x catalyst at 350 °C. [ABSTRACT FROM AUTHOR]

• Additional elements were introduced into crystalline trigonal Mo 3 VO x catalysts. • Local catalyst structure of the catalysts was strongly influenced the catalytic activity for selective oxidation of ethane, acrolein and allyl alcohol. • Trigonal Mo 3 VO x containing Fe in the crystal structure showed excellent acrylic acid yield by the one pot selective oxidation of allyl alcohol. • Partial location of metals in the micropore affected the catalytic properties. Crystalline "MoVO", "MoVCuO", "MoVFeO" and "MoVWO" catalysts with a trigonal symmetry were successfully synthesized and characterized. The influence of the as-obtained structures on catalytic performances in selective oxidation reactions was investigated. MoVFeO and MoVCuO accomodated Fe and Cu species inside heptagonal channels, while W in MoVWO was incorporated in pentagonal {Mo 6 O 21 }6− units. Whereas MoVO and MoVWO showed catalytic activity in the selective oxidation of ethane and acrolein, MoVFeO and MoVCuO performed very poorly in the same reaction, suggesting that the presence of empty heptagonal channels is related to ethane and acrolein activations. In the selective oxidation of allyl alcohol, substantial amounts of acrolein (formed by oxidative dehydrogenation) and propanal (formed by isomerization) were formed as primary products over MoVO and MoVWO, whereas MoVFeO and MoVCuO preferentially promoted the formation of acrolein. It was found that the local crystal structure around the heptagonal channel was related with a modification of the reaction pathway for the selective oxidation of allyl alcohol. Due to the prevention of isomerization over MoVFeO, a high acrylic acid yield of 83.1% from allyl alcohol was achieved at 350 °C over this sample. [ABSTRACT FROM AUTHOR]