Oxidic material comprising a zeolite having framework type AEI

A process for preparing an oxidic material comprising a zeolitic material having framework AEI and a framework structure comprising a tetravalent element Y, a trivalent element X, and O, the process comprising:

• (i) preparing a synthesis mixture comprising water, a source of Y, a source of X comprising sodium, an AEI framework structure directing agent, and a source of sodium other than the source of X;
• (ii) heating the synthesis mixture obtained from (i) to a temperature in the range of from 100 to 180° C. and keeping the synthesis mixture under autogenous pressure at a temperature in this range for a time in the range of at least 6 hrs, obtaining the oxidic material comprising a zeolitic material having framework AEI and a framework structure comprising a tetravalent element Y, a trivalent element X, and O, comprised in its mother liquor;
• (iii) cooling the mixture obtained from (ii) to a temperature in the range of 10 to 50° C.;
• and
• (iv) separating the oxidic material comprising a zeolitic material from the mixture obtained from (ii), said separating comprising:
• (iv.1) subjecting the mixture obtained from (ii) to a solid-liquid separation method comprising a filtration method or a spraying method,
• wherein the process for preparing the oxidic material does not comprise an addition of a source of X comprising sodium other than the step of (i) preparing the synthesis mixture comprising water, a source of Y, a source of X comprising sodium, and AEI framework structure directing agent, and a source of sodium other than the source of X,
• wherein the AEI framework structure directing agent according to (i) comprises an N,N—(C1-C3)dialkyl-(C1-C3)dialkylpiperidinium cation;
• wherein in the synthesis mixture prepared in (i) which is subjected to (ii), the molar ratio of the source of Y calculated as YO2, relative to the source of X calculated as X2O3, defined as YO2:X2O3, is in the range from 40:1 to 500:1;
• wherein in the synthesis mixture prepared in (i) which is subjected to (ii), the molar ratio of sodium calculated as Na2O, relative to the source of Y calculated as YO2, defined as Na2O:YO2, is in the range of from 0.25:1 to 0.50:1;
• and
• wherein the synthesis mixture prepared in (i) is heated to the temperature in (ii) with a heating rate in the range of from 0.5 to 4 K/min;
• wherein Y comprises a colloidal silica;
• wherein X is Al;
• wherein the source of X comprises NaAlO2, and
• wherein the source of sodium other than the source of X comprises NaOH.