This invention is directed to a molecular sieve composition or a catalyst
containing molecular sieve which has a relatively high residual silica
index, preferably at least about 1.5. The molecular sieve or catalyst can
be made by contacting a template-containing molecular sieve with a silicon
containing material having an average kinetic diameter that is larger than
the average pore diameter of the sieve or catalyst, and heating to leave
residual silica at the sieve or catalyst surface. The molecular sieve or
catalyst is particularly effective in making an olefin product from an
oxygenate feedstock.
