Oxygen-free direct conversion of methane and catalysts therefor

A method for converting methane to olefins, comprising:

• reacting a methane feedstock comprising methane in presence of a catalyst;
• and
• obtaining a product stream comprising olefins, aromatics, and hydrogen,
• wherein a conversion of methane is 8-50%, a selectivity of olefins is 30-90%, and a selectivity of aromatics is 10-70%,
• wherein the catalyst comprises a matrix of SiO2, Si3N4, SiC, SiCxOy (in which 4x+2y=4), SiOyNz (in which 2y+3z=4), SiCxNz (in which 4x+3z=4), or SiCxOyNz (in which 4x+2y+3z=4), one or more embedded metal dopants confined in the matrix,
• a plurality of active species, each of the plurality of active species is formed by replacing a Si, C, O, or N atom in the matrix with an atom of metal dopant,
• wherein an amount of the embedded metal dopant ranges from 0.001 wt % to 5 wt % to of a total weight of the catalyst, wherein x ranges from 0 to 1, y ranges from 0 to 2, and z ranges from 0 to 4/3, wherein the embedded metal dopant is selected from a group consisting of Li, Na, K, Mg, Al, Ca, Sr, Ba, Y, La, Ti, Zr, Ce, Cr, Mo, W, Re, Fe, Co, Ni, Cu, Zn, Ge, In, Sn, Pb, Bi, Mn, and mixtures thereof.