Carbon dioxide catalytic conversion

Low-valent rhenium complexes are effective in the catalytic reduction of carbon dioxide. The conversion can be accomplished photolytically or electrochemically and is of interest with regard to fuel production and greenhouse gas remediation [9]. Electrocatalytic reduction of CO2 to CO is initiated by the reduction of fac-Re(bpy)(CO)3Cl or a related complex and can be accomplished in homogeneous solution [54, 55] or on a polymer-modified electrode surface [56]. Catalytic current... 

Artificial enzymes can be useful for commercial applications even if they have low catalytic activity. When artificial enzymes are designed for chemical reactions such as photo-reduction of carbon dioxide or conversion of cellulose to glucose, they would contribute significantly to sustaining vitality of the Earth. 

Processes described in this chapter include (1) thermal oxidation of VOCs and odors, (2) catalytic oxidation of VOCs and odors, (3) catalytic oxidation of sulfur compounds to sulfur oxides, (4) catalytic conversion of organic sulfur compounds to hydrogen sulfide, (S) conversion of carbon monoxide to carbon dioxide (shift conversion), (6) conversion of oxides of carbon to methane (methanation), and (7) conversion of acetylene to ethylene (selective hydrogenation). 

Catalytic Oxidization. A principal technology for control of exhaust gas pollutants is the catalyzed conversion of these substances into innocuous chemical species, such as water and carbon dioxide. This is typically a thermally activated process commonly called catalytic oxidation, and is a proven method for reducing VOC concentrations to the levels mandated by the CAAA (see Catalysis). Catalytic oxidation is also used for treatment of industrial exhausts containing halogenated compounds. 

Fig. 3 showed the catalyst stability of Ni-Mg/HY, Ni-Mn/HY, and Ni/HY catalysts in the methme reforming with carbon dioxide at 700°C. Nickel and promoter contents were fixed at 13 wt.% and 5 wt.%, respectively. Initial activities over M/HY and metal-promoted Ni/HY catalysts were almost the same. It is noticeable that the addition of Mn and Mg to the Ni/HY catalyst remarkably stabilized the catalyst praformance and retarded the catalyst deactivation. Especially, the Ni-Mg/HY catalyst showed methane and carbon dioxide conversions more thrm ca. 85% and 80%, respectively, without significant deactivation even after the 72 h catalytic reaction. 

In our previous work [8], we rqjorted the synthesis of (2-oxo-l,3-dioxolan-4-yl)methacrylate (DOMA) finrn carbon dioxide and glycidyl methacrylate (GMA) using quaternary salt catalysts. In the present work, we studied the catalytic pra rmance of alkyhnethyl imidazolium salt ionic liquid in the synthesis of polycarbonate from the copolyraerization of CO2 with GMA. The influences of copolymerization variable like catalyst structure and reaction tenperature on the conversion of GMA and the yield of the polycarbonate have been discussed. 

After the reforming reaction, the gas is quickly cooled down to about 350 450 °C before it enters the (high-temperature) water-gas shift reaction (CO shift). Here, the exothermic catalytic conversion takes place of the carbon monoxide formed with steam to hydrogen (H2) and carbon dioxide (C02) in the following reaction ... 

An enzyme is a protein that speeds up a biochemical reaction without itself experiencing any overall change. In chemical language, such a compound is called a catalyst and is said to catalyze a reaction. Chemists employ a variety of compounds as laboratory catalysts, and many industrial chemical processes would be impracticably slow without catalysis. An automobile s catalytic converter makes use of a metal catalyst to accelerate conversion of toxic carbon monoxide in the exhaust to carbon dioxide. Similarly, our bodies biochemical machinery effects thousands of different reactions that would not proceed without enzymatic catalysis. Some enzymes are exquisitely specific, catalyzing only one particular reaction of a single compound. Many others have much less exacting requirements and consequently exhibit broader effects. Specific or nonspecific, enzymes can make reactions go many millions of times faster than they would without catalysis. 

Much of the work on the photoreduction of carbon dioxide centres on the use of transition metal catalysts to produce formic acid and carbon monoxide. A large number of these catalysts are metalloporphyrins and phthalocyanines. These include cobalt porphyrins and iron porphyrins, in which the metal in the porphyrin is first of all photochemically reduced from M(ii) to M(o), the latter reacting rapidly with CO to produce formic acid and CO. ° Because the M(o) is oxidised in the process to M(ii) the process is catalytic with high percentage conversion rates. However, there is a problem with light energy conversion and the major issue of porphyrin stability. 

For NiO(200), the initial heat of reaction is 90 kcal. per mole (20). Hence, a larger fraction of the carbon dioxide formed remains in the adsorbed state, and the catalytic activity decreases rapidly, after the conversion of increasing amounts of the stoichiometric mixture [Figure 4B dose A after conversion of 0.4 cc. per gram, dose B after conversion... 

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