It looks to be Pachira Macrocarpa. I have a large one. Some of the leaves are 10"-12" across. Will certainly make being bonsai a challenge. Good luck.

randy

I have one also, not sure of the actual name, but its also refered to as a "Money Tree". mine is very easy to maintain, and if you want to keep it as a trimmed small bonsi, you should snip off all of the new growth. But I dont do that, I have seen them almost three to four feet tall and hope that someday mine will be that large as well. Good luck!