Frequency-response chemisorption

Frequency Response Chemisorption Studies of Carbon Monoxide Hydrogenation Catalysts... 

The role of the support on hydrogen chemisorption on supported rhodium catalysts was studied using static and frequency response techniques. In all Instances, several klnetlcally distinct H2 cheml-sorptlve sites were observed. On the basis of the kinetics, at least one site appears to sorb H2 molecularly at temperatures below 150°C, regardless of the support. At higher temperatures, a dissociative mechanism may become dominant. Inducement of the SMSI state In Rh/T102 does not significantly alter Its equilibrium H2 chemisorption. 

GOODWIN ET AL. Frequency Response Chemisorption Studies P QAUQE... 

Figure 1. Schematic diagram of frequency response chemisorption apparatus.

Studies of the static and frequency response chemisorption of hydrogen on Rh catalysts supported on SlOo and TIO7 have shown that ... 

Figure 5 shows the two curves recorded by EQCM for the AN electropolymerization in DMF. The voltammogram (full line) expectedly shows the two reduction waves, I and II, on the Pt sensor. Moreover, the vibration frequency of this cathode (dotted line) decreases at the potential of the first peak, in accordance with PAN chemisorption responsible for an increase in the sensor mass. Consistent with previous observations (Sertion 4.36.2.1), the initial frequency is restored at the potential of the second redurtion wave (at -3.25 V, A/=0), which confirms that the previously chemisorbed/grafted chains are released from the cathode surface and grow in the electrol)4ic solution. 

---