制备催化剂所用的还原方法？
做多相催化少不了的就是用H2还原了．可是最近遇到个问题，就是我所用的载体是自制的．浸渍上了Pd, Cu后，催化剂的颗粒还是较细．再用H2还原的话恐怕会把进气管堵住．试了好些次都会出现这样的情况．现在我准备采用的是用甲酸钠（甲醛）还原的方法．我以前看过的文献有这样的介绍．好象是大化所李灿院士指导的博士生的论文，里面提到过用H2还原和甲酸钠或甲酸还原的对比．H2还原的活性并不比其他方法的好多少．晕哦，想找的时候偏偏就是找不到．都来说说看你们所用的方法吧．
找到一篇JOC的文章．
Gold on carbon. (a) Incipient wetness impregnation.
The support (2 g) was impregnated with 1 ml of 0.1M
HAuCl4 diluted with distilled water to a volume equal to
its pore volume. The suspension was mixed for 20 min and
then added to a hot solution of HCOONa (20 ml of water
and 200 mg of sodium formate).
(b) Deposition?precipitation method. The solution of
HAuCl4 0.1M(1 ml) was diluted with distilled water (10 ml)
and a saturated solution of Na2CO3 was added until a fixed
pH of 10 was reached. Then the mixture was added to a
stirred slurry of carbon (2 g) in distilled water (20 ml). The
slurry was allowed to stand for 1 h and then heated to 343K
and reduced by adding HCHO 37% (1.5 ml) dropwise.
On carbon support we have some evidence that the carbon
itself acts as the reductant. In fact a catalyst prepared
without adding HCHO is already active (although to in a
minor extent) and contains all the gold added (ICP analysis).
The HCHO is added to ensure a complete reduction
of gold.
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