Chemical waves in the O + H reaction on a Rh(111) surface alloyed with nickel. II. Photoelectron spectroscopy and microscopy.

Chemical waves in the H + O reaction on a Rh(111) surface alloyed with Ni [Θ < 1.5 monolayers (ML)] have been investigated in the 10 and 10 mbar range at T = 773 K using scanning photoelectron microscopy and x-ray photoelectron spectroscopy as in situ methods. The local intensity variations of the O 1s and the Ni 2p signal display an anticorrelated behavior.

Chemical waves in the O + H reaction on a Rh(111) surface alloyed with nickel. I. Photoelectron emission microscopy.

Chemical waves that arise in the H + O reaction on a bimetallic Rh(111)/Ni surface have been studied in the 10 and 10 mbar range at T = 773 K with photoelectron emission microscopy (PEEM), low-energy electron diffraction (LEED), and Auger electron spectroscopy (AES). Nickel coverages of 0.3, 0.

Traveling interface modulations and anisotropic front propagation in ammonia oxidation over Rh(110).

The bistable NH3 + O2 reaction over a Rh(110) surface was explored in the pressure range 10(-6)-10(-3) mbar and in the temperature range 300-900 K using photoemission electron microscopy and low energy electron microscopy as spatially resolving methods. We observed a history dependent anisotropy in front propagation, traveling interface modulations, transitions with secondary reaction fronts, and stationary island structures.