If your sample is nano-powder, a small amount of your catalyst nano-powder sample ( one or two grains) is dispersed in ethanol (10 ml). Every step is taken very carefully to avoid the contamination. Place a droplet of the catalyst nano-powder suspension on the TEM grid using a glass dropper (cleaned and washed) then allow the ethanol to evaporate (minimum 24 hours). after completing this protocol sample grid insert the sample holder and insert the TEM.