The invention relates to a conversion process of a feedstock, preferably
an oxygenated feedstock, into one or more olefin(s), preferably ethylene
and/or propylene, in the presence of a molecular sieve catalyst
composition that includes a molecular sieve and a Group 3 metal oxide
and/or an oxide of a Lanthanide or Actinide series element. The invention
is also directed to methods of making and formulating the molecular sieve
catalyst composition useful in a conversion process of a feedstock into
one or more olefin(s).