Ostwald 1902 ammonia oxidation

Currently, nitric acid is manufactured exclusively by catalytic oxidation of ammonia. Platinum or platinum-rhodium is an effective catalyst of this oxidation (Ostwald process). Three basic steps in such ammonia oxidation process are (1) oxidation of ammonia to form nitric oxide ... 

Researchers returned to the oxidation of ammonia in air, (recorded as early as 1798) in an effort to improve production economics. In 1901 Wilhelm Ostwald had first achieved the catalytic oxidation of ammonia over a platinum catalyst. The gaseous nitrogen oxides produced could be easily cooled and dissolved in water to produce a solution of nitric acid. This achievement began the search for an economic process route. By 1908 the first commercial facility for production of nitric acid, using this new catalytic oxidation process, was commissioned near Bochum in Germany. The Haber-Bosch ammonia synthesis process came into operation in 1913, leading to the continued development and assured future of the ammonia oxidation process for the production of nitric acid. 

Ammonia oxidation (Ostwald) 1906 Nitric acid production 4NH3 -b 5O2 — 4NO -b 6H2O 90%Pt-l 0% Rh wire gauze... 

Present-day nitric acid production is almost entirely via the oxidation of ammonia and absorption of the oxidation products in water. The chemistry of this process was proven experimentally by Kuhlmann in 1839, but had to wait for the development of an economical route to ammonia before it could become commercially significant [38]. Ostwald, working in Germany in about 1900, reexamined and extended Kuhlmann s data and established the proper conditions required for the ammonia oxidation step. Very shortly after this plants operating on these principles were constructed both in Germany and the U.S. Since 1980, 3-5 million metric tonnes of nitric acid (100% basis) have been produced annually in Germany, and 7-9 million tonnes in the U.S. (Table 11.7). 

In a continuous flow reactor, these quantities will, of course, again depend on the external parameters pi and T, as will be illustrated in the following with the example of ammonia oxidation on a Ru02(1 10) surface [34]. This Ostwald process is the basis for large-scale production of nitric acid that operates with platinum-based catalysts at temperatures >1000K where the rate... 

A few industrial important heterogeneous catalysts are prepared by melt processes. Examples are the Fe-catalyst for the Haber-Bosch process and the Pt/Rh-net for the ammonia oxidation in the Ostwald process (see also Section 6.4). Melting is also the initial process step for the preparation of Raney-nickel and Raney-copper catalysts. For these catalysts an alloy of Ni/Cu and A1 is prepared by melting. This alloy is later treated with NaOH to dissolve the A1 from the solid to create pores and reactive surface sites. Raney-Ni and Raney-copper are very important hydrogenation catalysts. 

In 1838, Frederic Kuhlmann discovered die formation of nitrogen oxide (NO) during die catalytic oxidation of ammonia. Wilhelm Ostwald developed die production mediods in 1902 and established die base for today s major commercial processes. However, industrial production began only after Haber and Bosch developed the synthesis of ammonia around 1916. 

The modem process for manufacturing nitric acid depends on the catalytic oxidation of NH3 over heated Pt to give NO in preference to other thermodynamically more favour products (p. 423). The reaction was first systematically studied in 1901 by W. Ostwald (Nobel Prize 1909) and by 1908 a commercial plant near Bochum. Germany, was producing 3 tonnes/day. However, significant expansion in production depended on the economical availability of synthetic ammonia by the Haber-Bosch process (p. 421). The reactions occurring, and the enthalpy changes per mole of N atoms at 25 C are ... 

H.20 The first stage in the production of nitric acid by the Ostwald process is the reaction of ammonia gas with oxygen gas, producing nitric oxide gas, NO, and liquid water. The nitric oxide further reacts with oxygen to produce nitrogen dioxide gas, which, when dissolved in water, produces nitric acid and nitric oxide. Write the three balanced equations that lead to the production of nitric acid. 

Interestingly, this situation is very different when we consider activation of NH3 or H2O by coadsorbed O. This would typically occur in the Ostwald reaction that oxidizes ammonia to NO or the methane reforming reaction in which CH4 reacts with O2 or H2O to give CO, CO2, and H2. 

Ammonia is also the starting material for the production of nitric acid, and the first step is oxidation of ammonia by the Ostwald process. 

In the early 1900s, it was discovered that ammonia could be oxidized in the presence of a platinum catalyst (the Ostwald process). 

Ostwald The basis of the modem family of processes for making nitric acid by the catalytic oxidation of ammonia. 

One of the steps in the Ostwald process for the production of nitric acid involves the oxidation of ammonia. 

Platinum also is used extensively as a catalyst in hydrogenation, dehydrogenation, oxidation, isomerization, carbonylation, and hydrocracking. Also, it is used in organic synthesis and petroleum refining. Like palladium, platinum also exhibits remarkable abdity to absorb hydrogen. An important application of platinum is in the catalytic oxidation of ammonia in Ostwald s process in the manufacture of nitric acid. Platinum is installed in the catalytic converters in automobile engines for pollution control. 

The importance of catalysts in chemical reactions cannot be overestimated. In the destruction of ozone previously mentioned, chlorine serves as a catalyst. Because of its detrimental effect to the environment, CFCs and other chlorine compounds have been banned internationally. Nearly every industrial chemical process is associated with numerous catalysts. These catalysts make the reactions commercially feasible, and chemists are continually searching for new catalysts. Some examples of important catalysts include iron, potassium oxide, and aluminum oxide in the Haber process to manufacture ammonia platinum and rhodium in the Ostwald synthesis of nitric... 

Nitric acid can be prepared by several methods, but the primary method is by the oxidation of ammonia using the Ostwald method, which was named for Wilhelm Ostwald (1853-1932). The Ostwald method enabled the Germans to produce explosives in World War... 

Ostwald process The production of nitric acid by the catalytic oxidation of ammonia, overall order The sum of the powers to which individual concentrations are raised in the rate law of a reaction. Example If the rate = [S02][S03]" l/2, then the overall order is f. 

PROBLEM 8.16 Use the information in Table 8.2 to calculate AH° (in kilojoules) for the reaction of ammonia with 02 to yield nitric oxide (NO) and H20(g)/ a steP m the Ostwald process for the commercial production of nitric acid. 

In the first step of the Ostwald process for the synthesis of nitric acid, ammonia is converted to nitric oxide by the high-temperature reaction... 

Nitric acid is produced industrially by the multistep Ostwald process, which involves (1) air oxidation of ammonia to nitric oxide at about 850°C over a platinum-rhodium catalyst, (2) rapid oxidation of the nitric oxide to nitrogen dioxide, and (3) disproportionation of N02 in water ... 

E. C. C. Baly and H. M. Duncan studied the decomposition of ammonia by means of a hot platinum wire. Two types of ammonia may be prepared—an inactive and an active modification—which are decomposed to different extents by the same quantity of energy. The active form is obtained by the slow withdrawal of ammonia from a cylinder containing the compressed gas by warming the cone. aq. soln. and drying the gas by quicklime and by isothermal evaporation of the liquefied gas at its b.p. The inactive form is obtained by the rapid evaporation of the liquefied gas. The inactive gas slowly recovers its activity on remaining in contact with the liquefied gas. The same effect can be produced by gently warming the gas by means of a platinum wire heated at 200°. In order to observe these phenomena, the platinum wire must be activated in the same way as is customary in W. Ostwald s process for the catalytic oxidation of ammonia in air to nitric acid. Alternatively,... 

The appearance of gauzes is illustrated by Figures 5 and 6 (9). The use of noble metal gauzes goes back to the beginning of the 20th century for the oxidation of ammonia into NO. This work followed up work of Ostwald, who applied platinized asbestos and later a roll of corrugated strip of Pt. Probably, this was the first application of a structured reactor. 

---