*2.1. Synthesis of MER Zeolite*

The synthesis of MER zeolite (W-3) was carried out as follows. Typically, Al(OH)3 (1.448 g, extra pure, Acros Organics) and KOH (4.290 g, 85%, QRëC) were mixed in distilled water (11.876 g). The mixture was magnetically stirred at 100 °C for 16 h. The clear aluminate solution was then slowly introduced into the silicate solution comprising HS-40 (9.763 g, 40% SiO2, Sigma–Aldrich) and distilled water (15.022 g). The resulting hydrogel with a molar composition of 1Al2O3:7SiO2:3.5K2O:196H2O was stirred for another 10 min before crystallization at 180 ◦C for 14 h. The solid product obtained was purified with distilled water using high speed centrifugation (10,000 rpm, 10 min) until pH 7 and the sample was freeze-dried. Other samples were also prepared by varying the synthesis conditions as summarized in Table 1 using the same procedure. The samples were labelled as W-*n* where *n* was the number of the sample.
