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An illustrative example is the effect of catalysts to speed the decomposition of hydrogen peroxide into water and oxygen: . 2 H 2 O 2 → 2 H 2 O + O 2. This reaction proceeds because the reaction products are more stable than the starting compound, but this decomposition is so slow that hydrogen peroxide solutions are commercially available.
Vanadium(V) oxide (in the contact process), finely divided iron (in the Haber process), and nickel (in catalytic hydrogenation) are some of the examples. Catalysts at a solid surface (nanomaterial-based catalysts) involve the formation of bonds between reactant molecules and atoms of the surface of the catalyst (first row transition metals ...
Three numbers immediately following the NMC abbreviation indicate the relative stoichiometry of the three defining metals. For example, an NMC molar composition of 33% nickel, 33% manganese, and 33% cobalt would abbreviate to NMC111 (also NMC333 or NCM333) and have a chemical formula of LiNi 0.33 Mn 0.33 Co 0.33 O 2.
Typical catalysts are platinum, and redox-active oxides of iron, vanadium, and molybdenum. In many cases, catalysts are modified with a host of additives or promoters that enhance rates or selectivities. Important homogeneous catalysts for the oxidation of organic compounds are carboxylates of cobalt, iron, and manganese
The molybdenum-based mixed oxides are versatile catalysts in the chemical industry. Some examples are the catalysts for the oxidation of carbon monoxide, propylene to acrolein and acrylic acid, the ammoxidation of propylene to acrylonitrile. [79] [80] Molybdenum carbides, nitride and phosphides can be used for hydrotreatment of rapeseed oil. [81]
Some of the large chemical processes that use catalysis today are the production of methanol and ammonia. Both methanol and ammonia synthesis take advantage of the water-gas shift reaction and heterogeneous catalysis, while other chemical industries use homogenous catalysis. If the catalyst exists in the same phase as the reactants it is said ...
Common Lewis acid catalysts are based on main group metals such as aluminum, boron, silicon, and tin, as well as many early (titanium, zirconium) and late (iron, copper, zinc) d-block metals. The metal atom forms an adduct with a lone-pair bearing electronegative atom in the substrate, such as oxygen (both sp 2 or sp 3), nitrogen, sulfur, and ...
The 1990s brought forward a new range of post-metallocene catalysts. Typical monomers are nonpolar ethene and propene. The development of coordination polymerization that enables copolymerization with polar monomers is more recent. [4] Examples of monomers that can be incorporated are methyl vinyl ketones, [5] methyl acrylate, [6] and ...