10.1021/acs.jchemed.9b00351.s010
Petrus
C. M. Laan
Petrus
C. M.
Laan
Mareena C. Franke
Mareena C.
Franke
Richard van Lent
Richard
van Lent
Ludo B. F. Juurlink
Ludo B. F.
Juurlink
Heterogeneous Catalytic Oxidation of Ammonia by Various
Transition Metals
American Chemical Society
2019
catalyst surface
power supply
butane flame
Sabatier principle
Various metal catalyst wires
Active catalysts
Various Transition Metals
Heterogeneous Catalytic Oxidation
oxidation
illustration
Thermal heating
10 elements Rh
metal wires
ammonia-to-oxygen ratio
grayish smoke
group 9
2019-07-31 13:29:50
Media
https://acs.figshare.com/articles/media/Heterogeneous_Catalytic_Oxidation_of_Ammonia_by_Various_Transition_Metals/9199097
A well-known demonstration is adapted
to simplify the illustration
of heterogeneous catalytic oxidation of ammonia. Various metal catalyst
wires are placed above the liquid level in a flask containing concentrated
ammonia. After brief preheating, some metal wires continue to glow,
providing visual evidence of an overall exothermic reaction taking
place at the catalyst surface. Thermal heating by a butane flame prior
to insertion and <i>in situ</i> resistive heating using
a power supply yield identical results. Active catalysts are the group
9 and 10 elements Rh, Ir, Pd, and Pt. Besides the illustration of
the Sabatier principle, the effect of the ammonia-to-oxygen ratio
can also be visualized, and active metals vary in the production of
a grayish smoke. These observations provide a starting point to discuss
catalytic selectivity, a topic of great relevance to industrial catalytic
oxidation of ammonia.