Michael G. Palin

A small solid oxide fuel cell demonstrator for microelectronic applications

A key question relating to the application of solid oxide fuel cells (SOFCs) is the size of the smallest device which can be usefully operated. Previous studies have suggested that 1 kWe is the smallest power output that is reasonably attainable, with most applications in the larger power range around 200 kWe. In this paper we demonstrate that smaller SOFCs can be built, with possible applications to microelectronics and communications at remote sites where gas is available but batteries are expensive. Experiments are described on a three-cell device powered by butane. This was warmed up in minutes at a flow rate of 80 ml/min of butane to give an electrical output between 0.1 and 1 W. The cells were made of zirconium oxide extruded in thin-walled tube form, with nickel cermet anodes and lanthanum strontium manganite cathodes.

A 1000-cell SOFC reactor for domestic cogeneration

A cogeneration system was built using 1000 cells with the intention of supplying 30 kW of hot water and 500 W of power. The basis of the cogenerator was the small tubular SOFC design. 8Y zirconia was mixed into a plastic paste and extruded to form thin-walled tubes. The process produced a zirconia material with high strength and good electrical properties. After drying and firing to full density, electrodes were coated onto the inner and outer surfaces of the electrolyte, then sintered. Current collecting wires were wound around the tubular cells and the tubes were assembled into a reactor. Either hydrogen or a premix of natural gas and air was fed through the tubes and ignited by a hot wire. The ignition shock did not damage the cells in any way. Cycling was achieved within minutes. A steel heat exchanger/recuperator was used to feed hot air to the cell stack. The electrical output was measured via a potentiostat.

Enzymatic generation of planar chirality in the (arene)tricarbonylchromium series

Abstract Hydrolysis using pig liver esterase of the meso diesters [ortho-C 6 H 6 (CH 2 CO 2 R) 2 ]-Cr(CO) 3 (R = Me,Et) yields the half ester in good yield and high enantiomeric excess.

The first orthopalladation of a primary nitrobenzylamine. Synthesis of chiral cyclopalladated complexes derived from (S)-α-methyl-4-nitrobenzylamine

By refluxing a mixture of (S)-α-methyl-4-nitrobenzylamine and Pd(O2CMe)2(1 : 1) in acetone, complexes (S,S)-[{Pd[C6H3{CH(Me)NH2}-2-NO2-5](µ-X)}2](X = MeCO21a or Cl 1b) are obtained. Complex 1b can also be obtained by treating (S)-α-methyl-4-nitrobenzylamine hydrochloride with Pd(O2CMe)2(1 : 1) in acetone. These complexes are the first orthometallated complexes containing a primary amine with an electron-withdrawing group in the benzene ring. Complex 1a reacted with an excess of NaBr or Nal to give (S,S)-[{Pd[C6H3{CH(Me)NH2}-2-NO2-5](µ-X)}2](X = Br 1c or I 1d). Triphenylphosphine reacted with 1b or 1c to give (S)-[Pd{C6H3[CH(Me)NH2]-2-NO2-5}X(PPH3)](X = Cl 2a or Br 2b). The reaction of complex 1b with AgClO4(1 : 1) and an excess of pyridine (py) gave (S)-[Pd{C6H3[CH(Me)NH2]-2-NO2-5}(py)2]ClO43. Complex 1c reacted with 3 equivalents of RCCR (R = CO2Me) to give a tri-insertion reaction product, the crystal structure of which has been determined: space group P212121, a= 11.0969(14), b= 17.197(2), c= 19.604(3)A, R(F)= 0.041. The planar co-ordination at palladium is not significantly disturbed by a short contact of 2.600 A to the C atom of a CO2Me group. A cationic derivative of this complex has also been prepared.

Asymmetric biochemical reduction, acylation and hydrolysis in the (diene)Fe(CO)3 series: Experimental results and molecular modelling studies

Abstract Asymmetric reduction using bakers yeast and asymmetric acyl transfer using porcine pancreatic lipase may be used in the kinetic resolution and desymmetrization of acyclic (diene)Fe(CO) 3 complexes bearing CHO and CH 2 OH substituents respectively. The results may be interpreted in terms of current active site models for these biotranformations.

The solution structure and fluxional behaviour of cyclic and acyclic (diene) Fe(CO)2L complexes (L = phosphine, phosphite, isonitrile)

Variable temperature 13C and 31P NMR spectroscopy has been used to establish solution structures and conformer populations for a variety of cylic and acyclic (diene)Fe(CO)2L complexes (L = phosphine, phosphite, isonitrile). The solid state structures of (2,3-dimethylbutadiene)Fe(CO)2PPh3 and (trans,trans-2,4-hexadiene)Fe(CO)2PPh3 have been determined and used as a basis for molecular modelling of steric effects in these complexes.

Biochemical resolution and generation of planar chirality in formyl substituted (diene)Fe(CO)3 complexes

Abstract Kinetic resolution of (2,4-hexadien-1-al)Fe(CO) 3 and asymmetric reduction of (2,4-hexadien-1,6-dial)Fe(CO) 3 using bakers yeast proceed with high efficiency and enantioselectivity.

Diastereoselectivity in the bakers yeast reduction of [1-2H](sorbaldehyde)Fe(CO)3

Abstract Bakers yeast reduction of the faster reacting (2S) enantiomer of [1-2H](sorbaldehyde) Fe(CO)3 proceeds with complete diastereoselectivity. Little or no diastereoselectivity is observed in bakers yeast reduction of the slower reacting (2R) enantiomer or in the reduction of the racemic complex with NaBH4.

Enzymatic generation of planar chirality in the (arene)Cr(CO)3 series: experimental results and modelling studies

Abstract Hydrolysis using pig liver esterase of (benzene-1,2-diacetic ester)Cr(CO) 3 complexes generates the half-ester in high enantiomeric purity. The high enantioselectivity may be rationalised through substrate interaction with the Jones active site model of pig liver esterase.

Evidence for correlated rotation and diastereoisomer discrimination in (η4-diene)Fe(CO)2L complexes: the crystal and solution structures of (cyclohexadiene)Fe(CO)2P(o-tolyl)3 and (cycloheptadiene)Fe(CO)2(+)-PPh2(neomenthyl)

Abstract The solid state structure of (cyclohexadiene)Fe(CO) 2 P( o -tolyl) 3 reveals an exo 2 conformation for the phosphine. In solution, arene ring exchange in the phosphine and exchange of phosphine between equivalent basal positions of the square pyramid occur at equal rates. In solution, (cycloheptadiene)Fe(CO) 2 (+)-PPh 2 (neomenthyl) exhibits a diastereoselection between basal isomers, and crystallizes as a single diastereoisomer which has been structurally characterized.