Ahead Some Suggested Priorities for Future Research

Looking Ahead Some Suggested Priorities for Future Research 

General Comments on Vibrational Spectroscopic Experimental Techniques 

Although as yet seemingly restricted to above ca. 1500 cm 1 by the limited availability of tuneable infrared detectors, this technique also virtually eliminates gas-phase contributions to spectra. The pulsed lasers used also open up the possibilities of fast (nanosecond or less) kinetic studies of catalytic reactions. 

Raman spectra of adsorbed species, when obtainable, are of great importance because of the very different intensity distributions among the observable modes (e.g., the skeletal breathing frequency of benzene) compared with those observed by infrared spectroscopy and because Raman spectra of species on oxide-supported metals have a much wider metal oxide-transparent wavenumber range than infrared spectra. Such unenhanced spectra remain extremely weak for species on single-crystal surfaces, but renewed efforts should be made with finely divided catalysts, possibly involving pulsed-laser operation to minimize adsorbate decomposition. Renewed efforts should be made to obtain SER and normal Raman spectra characterizing adsorption on surfaces of the transition metals such as Ni, Pd, or Pt, by use of controlled particle sizes or UV excitation, respectively. 

In the infrared region, and possibly also by Raman spectroscopy, more studies should be made of catalysts and catalytic reactions carried out in situ. By use of conventional transmission infrared techniques, it is also 

---

XI. Looking Ahead Some Suggested Priorities for Future Research... 

---