A process for preparing a 2D-hexagonal ordered mesoporous silica material with a substantially uniform pore size in the range of 4 to 30 nm comprising the steps of: preparing an aqueous solution comprising an alkali silicate solution； preparing an aqueous solution comprising a poly(alkylene oxide) triblock copolymer and a buffer with a pH greater than 2 and less than 8, adding said aqueous alkali silicate solution to said aqueous solution giving a pH greater than 2 and less than 8 and allowing a reaction between the components to take place at a temperature in the range of 10 to 100° C., and filtering off, drying and calcinating the reaction product to produce said 2D-hexagonal ordered mesoporous silica material with a substantially uniform pore size. In an alternative procedure both aqueous solutions are fed as liquid streams into an elongated mixing receptacle having a first and a second opening such that the liquid streams of the solutions are each discharged independently into said first opening of said elongated mixing receptacle such that they directly impinge thereby giving a pH in the resulting mixture of greater than 2 and less than 8 and producing a reaction product at a temperature in the range of 10 to 100° C. in said elongated mixing receptacle, which upon emergence from said second opening of said elongated mixing receptacle is filtered off, dried and the surfactant removed.
