Józef Zawadzki (chemist)

Józef Zawadzki (July 14, 1886 in Warsaw – February 22, 1951 in Zalesie, near Warsaw) was a Polish physical chemist and technologist. Father of Tadeusz (Zośka) and Anna Zawadzka.

Zawadzki was a co-founder, President and Vice-President of the Polskie Towarzystwo Chemiczne. He was a professor (from 1923) and rector (1936–1939) of Warsaw University of Technology, and a member of the Polish Academy of Learning (since 1947).

The oldest and largest traditional lecture hall at the Warsaw University of Technology is named Prof. Józef Zawadzki Auditorium.[http://www.ch.pw.edu.pl/en/ The Faculty of Chemistry - Official Page, Warsaw University of Technology], retrieved 2008-05-28. {{webarchive |url=https://web.archive.org/web/20080430145124/http://www.ch.pw.edu.pl/en/ |date=April 30, 2008 }}

Research

His main field of research was physicochemical fundamentals of chemical technology. He was researching contact oxidation of ammonia, naphthalene and anthracene, mechanism of ammonia oxidation on platinum at low temperatures, reduction of iron dioxide by a methane, methods of obtaining aluminium oxide from Polish kaolinite and aluminosilicate, use of Polish anhydrite and gypsum deposit to production sulfuric acid and cementum, kinematics of thermal dissociation.

Under the German occupation of Poland during World War II, he was involved in the clandestine operation of the Warsaw University of Technology. Together with Marceli Struszyński, Zawadzki analyzed captured German V-2 rocket for its fuel composition. In 1947, he was recognized with a Doctor Honoris Causa.[http://www.technikumchemiczne.edu.pl/patron.html Technikum Chemiczne nr 3 in Warsaw, Poland], retrieved 2008-05-28. {{webarchive |url=https://web.archive.org/web/20080516102358/http://www.technikumchemiczne.edu.pl/patron.html |date=May 16, 2008 }}

=Mechanism of ammonia oxidation on platinum at low temperatures=

The mechanism of ammonia oxidation on platinum at low temperature was postulated by F. Rachsig (1927) and later adapted by Zawadzki (1948, 1950) to proceed via formation on imide (NH). In this proposal formation of nitroxyl and hydrazine (N₂H₄) is involved:Sobczyk (2003), p. 6.

: NH₃ + O_(a) → NH_(a) + H₂O

: NH_(a) + O_(a) → HNO_(a) + *

: NH_(a) + NH₃ → N₂H_4(a)

: HNO_(a) + NH₃ → N₂H_4(a) + ½O₂

: N₂H_4(a) + O₂ → N₂ + 2H₂O + *

Later, Y. M. Fogel (1964) disproved the Zawadzki theory that NH is formed via the oxidation of ammonia. In his proposal, N O is an important intermediate of the reaction. The formation of N₂O is not detected, therefore the mechanism does not involve its production.