Catalysts

[elemenope]

I understand that catalysts speed up reactions by "providing a new route" for the reaction to occur in which requires a lower activation energy. What exactly does that mean, provide a new route? How exactly does this happen, I am having a hard time envisioning it.....

[Symmetryigr8]

Inorganic catalysts provide a new surface for reaction to take place, they attract one reactant and so increase its concentration on the surface. Hence the rate of reaction increases by the surface. Catalytic converters in cars work like this so the converter has a honeycomb structure giving lots of surface area.