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The contact process is a method of producing sulfuric acid in the high concentrations needed for industrial processes. Platinum was originally used as the catalyst for this reaction; however, because it is susceptible to reacting with arsenic impurities in the sulfur feedstock, vanadium(V) oxide (V 2 O 5) has since been preferred.
Vanadium(V) oxide serves the crucial purpose of catalysing the mildly exothermic oxidation of sulfur dioxide to sulfur trioxide by air in the contact process: 2 SO 2 + O 2 ⇌ 2 SO 3 The discovery of this simple reaction, for which V 2 O 5 is the most effective catalyst, allowed sulfuric acid to become the cheap commodity chemical it is today.
Vanadium(V) oxide is a catalyst in the contact process for producing sulfuric acid. Vanadium compounds are used extensively as catalysts; [83] Vanadium pentoxide V 2 O 5, is used as a catalyst in manufacturing sulfuric acid by the contact process [84] In this process sulfur dioxide (SO 2) is oxidized to the trioxide (SO
Catalytic oxidations are common in biology, especially since aerobic life subsists on energy obtained by oxidation of organic compounds by air. In contrast to the industrial processes, which are optimized for producing chemical compounds, energy-producing biological oxidations are optimized to produce energy.
DDQ and an acid catalyst has been used to synthesise a steroid with a phenanthrene core by oxidation accompanied by a double methyl migration. [9] In the process, DDQ is itself reduced into an aromatic hydroquinone product. Sulfur and selenium are traditionally used in aromatization, the leaving group being hydrogen sulfide. [10]
If the catalyst and reaction conditions are indicative of low effectiveness, selective poisoning may be observed, where poisoning of only a small fraction of the catalyst's surface gives a disproportionately large drop in activity. [4] If η is the effectiveness factor of the poisoned surface and h p is the Thiele modulus for the poisoned case:
Bioenzymes are also bio catalyst. They are prepared by fermentation of organic waste, jaggery and water in ratio 3:1:10 for three months. It increases the soil microbe population and speeds up composting and decomposition and so is included in catalyts. It heals the soil. It is one of the best best organic liquid fertilizer. It is diluted with ...
The final step is reductive elimination of the two coupling fragments to regenerate the catalyst and give the organic product. Unsaturated substrates, such as C(sp)−X and C(sp 2)−X bonds, couple more easily, in part because they add readily to the catalyst.