Ketene (CH2=C=O) has been postulated as a key intermediate for the first olefin production in zeolite-catalyzed chemistry of methanol-to-olefins (MTO) and syngas-to-olefins (STO) processes. The reaction mechanism remains elusive, because short-lived ethenone ketene its derivatives are difficult to detect, which is further complicated by low expected concentration. We report on experimental dete...

Here we developed a new method to quantitatively characterize the spatial distribution of Brønsted acidity HZSM-5 zeolite on crystal grains level indirectly. The acid sites completely covered or blocked by previous coke deposition were released gradually from outer surface center via shrinking core mode isothermal oxidation with high temperature and low oxygen concentration. was obtained based ...

Abstract This study investigates the production of diesel fuels by integrated Fischer–Tropsch synthesis over a bifunctional cobalt catalyst consisting component (Co–Al 2 O 3 /SiO ) and zeolite-containing (ZSM-5). The catalytic properties were tested in continuous-flow reactor with stationary bed at 240–250°C, MPa, gas WHSV 1000 h –1 . effects SiO /Al ratio HZSM-5 zeolite on performance, deactiv...

Abstract The adsorption of methanol in HZSM-5 at low temperatures has long been regarded as an associative process involving hydrogen bonding to the acidic zeolite hydroxyl groups. Recent studies employing inelastic neutron scattering spectroscopy (INS) have reported that complete dissociation methoxylate occurs 298 K, and infrared evidence for a partial K also described. Here we investigate ap...

An elementary reaction during cracking of a hydrocarbon in a nanoporous silicalite catalyst includes ejection of a hydrid ion as shown in the picture. The reaction was simulated by means of quantum molecular dynamics.