Copper-nickel alloys, formic acid

Compensation trends found for decomposition of formic acid on metal (and other) catalysts are represented diagrammatically in Fig. 7. Line I (Table III, Q) refers to reactions over nickel and copper (3, 190, 194, 236), gold (5,189,237), cobalt (137,194), and iron (194) the observations included in this group were obtained by selection, since other metals, which showed large deviations, were omitted [see also (5), p. 422], Line I is close to that calculated for the reaction catalyzed by nickel metal (Table III, R) (3, 137, 189-194, 238). Lines II (19,233) and III (3, 234, 235) (Table III, O and P) refer to decomposition on silver. The other lines were found for the same rate process on IV, copper-nickel alloys (190) V, oxides (47, 137), VI, tungsten bronzes (239) and VII, Cu3Au (Table III, S) (240a). 

Volter and Alsdorf (52) obtained a relation of a very similar character for the dependence of the catalytic activity in formic acid decomposition on the composition of the nickel-copper alloys. However, extending the times of the alloy annealing for their better homogenization caused the maxima on the catalytic activity curves to disappear. 

Titanium resists corrosion well, but is expensive.95 Tantalum is also expensive. Stainless steel and other nickel alloys are cheaper for use in equipment and resist reagents such as formic acid.96 The commonly used Monel metal is an alloy of 66.5% nickel and 31.5% copper. One of the best steel alloys contains 20% chromium, 29% nickel, 2.5% molybdenum, and 3.5% copper. Its rate of corrosion is 28 p,m/yr. Lasershot peening can be used to treat the surfaces of metals to improve resistance to corrosion and extend the lifetime up to five times.97... 

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