Improvements to raney copper methanol synthesis catalysts through zinc impregnation

The leaching of CuAl₂ and a Cu-Al-Zn (43.5 wt.-%, Cu, 39.5 wt.-% Al, 17 wt.-% Zn) alloy in 6.1M sodium hydroxide and in 0.62M zincate in 6.1M sodium hydroxide has been investigated at 274 K and 303 K. The effects of leaching conditions on surface area development in the leached materials is also reported. The addition of zincate to the sodium hydroxide solution slows the leaching rate of both alloys, the greatest effect being observed for the Cu-Al-Zn alloy. The decrease in rate results in an increase in surface area. A competing process which causes rearrangement and growth of the copper crystallite limits the maximum attainable surface area, particularly at 303 K.