sc8b01543_si_001.pdf (379.53 kB)
Oxidation of Trace Ethylene at 0 °C over Platinum Nanoparticles Supported on Silica
journal contribution
posted on 2018-08-06, 00:00 authored by Shazia
S. Satter, Takuro Yokoya, Jun Hirayama, Kiyotaka Nakajima, Atsushi FukuokaOxidation of trace
ethylene (50 ppm) at 0 °C was systematically
studied using Pt nanoparticles supported on mesoporous silica (SBA-15)
in a fixed-bed flow reactor. The SBA-15 supported Pt catalyst (1.8
wt % Pt loading) exhibited an ethylene conversion higher than 99%
at the initial stage, which gradually began to decrease at 90 min
and reached 33% within 240 min. The CO2 yield was lower
than the corresponding ethylene conversion before the steady state
was reached. This was due to the formation of intermediates that were
stabilized on the catalyst surface. These intermediates could be recovered
in the form of CO2 by heating the spent catalyst in a mixed
N2 and He (1:19, v/v) flow at 150 °C. The addition
of water vapor to the catalyst bed decreased the original activity
drastically because physically adsorbed water molecules partly blocked
the active Pt sites. Control experiments using nonordered silica supports
(Aerosil 380 and 200) showed similar catalytic behavior as that observed
with SBA-15. The formation of highly dispersed Pt nanoparticles on
the silica surfaces is thus the key to the development of effective
Pt catalysts for low-temperature oxidation of ethylene.