ACID AND CATALYTIC PROPERTIES OF MNOM-ZRO2 (M = CA, BA, SM, YB) COMPOSITIONS

Influence of the nature of MnOm in zirconia-based systems MnOm−ZrO2 (M=Ca, Ba, Sm, Yb) of approximately equimolar composition on their acid and catalytic properties in oxidative conversion of methane (OCM) have been studied. The surface of MnOm−ZrO2 systems has been found to contain practically no Bronsted acid sites. Lewis acid sites are represented by three types of L-sites, their total concentration per m2 decreasing in the series (Zr, Ca)O2>(Zr, Sm)O2>(Zr, Yb)O2. Activity of the catalysts in the OCM reaction is proportional to the specific surface area. Their selectivity to ΣC2 hydrocarbons increases in the series (Zr, Ca)O2<(Zr, Sm)O2<(Zr, Yb)O2.