posted on 2020-11-05, 14:05authored byHao Hao, Baofang Jin, Wei Liu, Xiaodong Wu, Fengfu Yin, Shuang Liu
Developing platinum catalysts highly
active for hydrocarbon combustion
at low temperatures is crucial but yet challenging, since platinum
may convert into inert PtO<sub><i>x</i></sub> in oxidizing
atmospheres and deactivates during catalytic combustion. In this article,
a Pt@TiO<sub><i>x</i></sub>/TiO<sub>2</sub> catalyst with
platinum nanoparticles decorated by amorphous TiO<sub><i>x</i></sub> overlayers was synthesized via a strong metal–support
interaction (SMSI)-related strategy. The Pt-TiO<sub><i>x</i></sub> electronic interaction stabilized reactive Pt<sup>0</sup> sites
during reactions, resulting in outstanding activities and high stability
for C<sub>3</sub>H<sub>8</sub> and C<sub>3</sub>H<sub>6</sub> combustion.
The influences of sulfatescommon byproducts forming on catalysts
applied for automobile exhaust purificationwere studied by
monitoring the platinum states, the hydrocarbon adsorption behavior,
and the catalytic performance of sulfated Pt@TiO<sub><i>x</i></sub>/TiO<sub>2</sub> with <i>in situ</i> DRIFTS. It is
suggested that the sulfates promoted C<sub>3</sub>H<sub>8</sub> combustion
via heterolytic C–H bond activation on Pt<sup>δ+</sup>–(SO<sub>4</sub>)<sup>δ−</sup> couples, while
C<sub>3</sub>H<sub>6</sub> combustion was disfavored on the sulfated
catalyst because of inhibited O<sub>2</sub> activation.