| 摘要 |
A process for manufacture of a crystalline silver catalyst which includes the steps of: (a) providing an electrolyte solution having a concentration of at least 10g/l of dissolved silver ions wherein said electrolyte solution has (i) minimal copper ion concentration; (ii) a pH greater than 4; and (iii) contains a complexing agent which generates complex silver cations in solution; (b) subjecting the electrolyte solution to electrolysis in an electrolytic cell having silver anode(s) of at least 90 % purity and having a concentration of copper of less than 10 % and cathodes which are formed from conductive but chemically inert material wherein said electrolysis is conducted at a temperature of 10 DEG C-40 DEG C and at a current density of greater than 20 A/m<2>; and (c) isolating crystalline silver from the electrolytic cell which has a packing density of less than 2.5 g/ml. There is also provided crystalline catalyst for efficient conversion of methanol to formaldehyde, having a packing density of less than 2.5 g/ml. |
