Which Zeolites can be prepared under atmospheric pressure without using any template (organic or other) using only aluminium source and silica source ?
zeolites ZSM-5 and silica nano-sized zeolite Y are easy types. Template and even solvent-free for ZSM-5, see http://dx.doi.org/10.1007/s10934-008-9200-4 and DOI:10.1039/C9NA00399A