PtRh catalyst

Barbier, Jr., J., and Duprez, D. 1993. Reactivity of steam in exhaust gas catalysis. I. Steam and oxygen/steam conversions of carbon monoxide and of propane over PtRh catalysts. Appl. Catal. B Environ. 3 61-83. 

M Sh and RhPt sites on nano-scale area of SCCO2 PtRh catalysts... 

The presence of a PtRh gauze catalyst catalyzes the reactants along the NO pathway with a selectivity of 98%. Therefore although the free energy is more favorable and the equilibrium constant for the N2 reaction is 105 times greater, the highly selective PtRh catalyst promotes the NH3 oxidation reaction to NO. In contrast the presence of Pd favors the N2 product. In each case the catalyst respects the equilibrium constant but directs the reactants to specific products. 

Figure 7J. Effecl of the metallic phase composition on the OSC at 4S0X for alumina (triangles) and ceria-alumina (squares) supported bimetallic PtRh catalysts.

The PtRh catalyst is severely affected by the engine bench-ageing while, again, the PdRh catalyst is much more resistant to this treatment. This point will be discussed further. 

The catalytic results confirm that the PtRh catalyst is rapidly deactivated when it is aged in engine bench, while the PdRh catalyst keeps a better light-off... 

Barbier Jr, J., and D. Duprez, 1995, Reactivity of steam in exhaust catalysis. Part II. Sintering and regeneration of Rh and PtRh catalysts in propane oxidation, in Catalysis and Automotive Pollution Control III, eds A. Frennet and J.-M. Bastin (Elsevier, Amsterdam) pp. 73-84. 

REACTIVITY OF STEAM IN EXHAUST GAS CATALYSIS. PART II SINTERING AND REGENERATION OF Rh AND PtRh CATALYSTS IN PROPANE OXIDATION... 

PtRh catalysts are commonly used in catalytic converters for eliminating pollutants (CO, hydrocarbons, NOx) from exhaust gases [1]. In the first part of our work [2], we investigated, on Pt(lwt.-%), Rh(0.2wt.-%) and... 

The aim of this work is to study the sintering of Rh and PtRh catalysts by means of oxidation and steam reforming activities in propane conversion. Changes in the steam reforming activity have been compared with those obtained in cyclopentane hydrogenolysis, a reaction extremely sensitive to the state of Rh in the catalyst [12]. 

Fig 4 Oxidation activities of PtRh catalysts Effects of thermal treatments... 

It has been evidenced that among the various unsaturated hydrocarbons, alkynes show the largest inhibiting effect on all oxido-reduction reactions occuring on a PtRh catalyst, i.e. non-alkyne hydrocarbons, CO and NO are not converted until alkynes are eliminated,... 

EFFECTS OF SINTERING AND OF ADDITIVES ON THE OXYGEN STORAGE CAPACITY OF PtRh CATALYSTS. 

Figure 2. Effect of sintering on the OSC of PtRh catalysts supported on alumina...

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