LAUSR

Abstract The methanol-to-dimethyl ether (MTD) process has been considered one of the potential methods for manufacturing environmentally friendly fuel, i.e., dimethyl ether (DME). The process requires an efficient, stable, and sustainable catalyst. Herein, metal-organic frameworks (MOF-5, zinc-terephthalate framework) and ZIF-8 (zeolitic imidazolate framework, zinc-imidazolate) were used as sacrificial precursors for the fabrication of MOF-derived ZnO@carbon (ZnO@C) via carbonization at different temperatures. The materials were characterized using X-ray diffraction (XRD), thermal analysis (thermogravimetric analysis (TGA) and differential thermal analysis (DTA)), X-ray photoelectron spectroscopy (XPS), Fourier transforms infrared (FT-IR), and nitrogen adsorption-desorption isotherms. The material's acidity was evaluated using isopropyl alcohol dehydration, chemisorption, and pyridine-temperature programming desorption (TPD) analysis. Data analysis reveals that the acidity of ZnO@C is due to Bronsted acidic sites of weak and intermediate strength. ZnO@C catalysts showed an excellent catalytic conversion (100%) towards DME via methanol dehydration with a selectivity of 100%. They displayed a high conversion and selectivity, increasing the percentage of methanol in the reacting stream and gas hourly space velocity (GHSV). They can be recycled several times with high catalytic activity and long-term stability for 160 h.