The invention relates to a molecular sieve catalyst composition, to a method of making or forming the molecular sieve catalyst composition, and to a conversion process using the catalyst composition. In particular, the invention is directed to a making a molecular sieve catalyst composition by forming a slurry by combining a molecular sieve, a binder and a matrix material, wherein the slurry has a pH, above or below the isoelectric point of the molecular sieve. The catalyst composition has improved attrition resistance, particularly useful in a conversion process for producing olefin(s), preferably ethylene and/or propylene, from a feedstock, preferably an oxygenate containing feedstock.