Hi Nelson,
Unfortunately, there is a limited amount of support we can provide for centOS installations, as we don't test against this O/S or maintain documentation to support it.
That said, there are a number of other users who are using either centOS or RHEL successfully. We try to tag posts for future reference - here you can see all posts tagged "centOS":
For example, you might want to check out this thread, which contains user-submitted resources on getting AtoM running on centOS 7:
I also tried searching for your error message in the forum. In both cases I found where users reported a similar error, it ended up being the PHP version that was the issue, and upgrading helped to resolve it. See:
What version of PHP do you have installed? Based on other posts, it looks like PHP 5.6 has worked for previous users.
You will also want to make sure you've properly installed all the additional PHP extensions and libraries. The thread linked above with the installation guide for centOS has some good suggestions on this.
Best of luck!