Protocol, catalyst performance testing

In combinatorial protocols, n experiments are performed at the same time in the same vessel. This methodology is the most efficient in terms of time and resources, but can only be applied in discrete cases in homogeneous catalysis. Indeed, the efficiency of a catalyst can only be measured when it is submitted to the reactants. Testing a mixture of catalysts in solution would give the overall efficiency of the mixture, without any indications about individual performances. 

Catalytic tests were carried out following a protocol that allowed establish relationships between the characteristics of fresh and spent catalysts and the catalytic performance. Specifically, within the first 5-10 hours reaction time, the catalytic performance was not stable, due to variations in samples characteristics. Therefore, two different sets of results were taken, the first after less than 1 hour (representative of fresh samples), and the second one after 3-4 hours (representative of spent samples). Only in the case of the equilibrated sample, no difference was found between the characteristics of samples eq and eqsp (Tables 1 and 2) for this catalyst, also the catalytic performance did not vary at all during catalytic tests. 

Ceria-containing samples were prepared that showed a lower tendency towards coke formation, which was most pronounced for an Rh/Pt/Ce02 catalyst. It showed no measurable deactivation for all reaction temperatures applied in the test protocol. Hence this catalyst showed the best performance of all the samples discussed above. For this Rh/Pt/Ce02 catalyst, which was identified as the best catalyst regarding activity, selectivity and deactivation by coke formation, the effect of increasing the S/C ratio was determined at temperatures between 650 and 750°. These measure-... 

Simple synthetic protocols for carbon-carbon and carbon-nitrogen bond formation using an air-stable palladium catalyst bearing an NHC ligand have been presented. The (IPr)Pd(allyl)Cl catalyst can be prepared on a large scale in high yield, better yet it is commercially available. Initial catalyst testing was performed on a small scale but the ease with which the described chemistry can be scaled up has now been shown. 

FIG. 13 Fabric detergency performance of methyl ester ethoxylate vs. conventional surfactants. (Conditions, test method, and protocol described elsewhere [15], descriptions of reference surfactants are given in Table 1 distribution for C -is methyl ester = 57% C12, 23% C14, 12% Cig, and 8% Cig MEEs prepared using calcium/aluminum alkoxide catalyst. (From Ref. 27.)... 

Eleclro-catalyst type/substrate or support Preparation method Stmctural characteristics Noble metal loading (mg cm ) Test protocol Performance Ref... 

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