I know RA gives their definition somewhere…but I have searched and cannot find it.
Here is a definition I like I found online: an agent that provokes or speeds significant change or action. OR - a person or thing that precipitates an event or change.
I want to know what YOUR personal thoughts are on what catalyst means to you. 
I believe Ra said that catalyst is anything that assaults the senses.
I like that Anthro… 
Is it catalyst of the body, the mind or the spirit? Body catalyst triggers your five senses so anytime you taste or touch or hear something even see it is a catalyst of the body. Catalyst of the mind for me would be your thoughts and the chatter of the physical mind and if someone says something triggering to you and you just can’t shake it mentally. Catalyst of the spirit I believe is quite subtle since the spirit operates in time/space while our minds and body are in space/time. That’s why Ra says when we look at our spirit it looks like an unmoving darkness just like the tarot card the devil or matrix of the spirit.
The catalyst, within the incarnation, is all the events that you’re experiencing through your senses within the incarnation.
Given the events correlate with each others due to action->reaction law, people usually refer to this as “chain of events”.
That’s a good definition I think. In Law of One terms I haven’t looked up much about what catalyst means. My impression is that it means an obstacle or problem for a person that has the effect of speeding up the spiritual development of the individual or groups of individuals.
similar to a catalyst in chemistry
There may be some sense of squandered opportunity
or a pain of missed opportunity at play in it, which
might compel rising to action, or not.
lol. opportunities have a mind to come back, 
Just like someone using a catalyst in a chemical experiment, if the experiment fails, they might switch to another catalyst to continue the experiment, even though the experiment’s goal remains the same.
The catalyst, in short, is anything that drives you to seek and evolve more deeply on the spiritual path.
What matters most about the catalyst is your awareness of it, whether it is a catalyst or not. When you start paying constant attention to everything around you or within you, and the observer becomes present through you most of the time, the intensity of the catalysts increases and their presence becomes more significant to you as catalysts.
When you are not attentive, many catalysts will remain in a state of organized or random repetition according to your beliefs, thoughts, and roles.
The state of the catalyst varies depending on whether it is for the mind, body, or soul.
However, all catalysts come with different emotional states.