Hi Michael.

Leaf scorch can be caused by high temperatures, dry winds, watering, or soil. Is your two year old maple on a site that has great drainage? if yes, it would be best to water deeply and regularly. Trees with circling or girding roots can also exhibit drought response. Do you think when it was planted that the roots were spread out properly? In short, I can't tell exactly what is causing the symptom but please do not fertilize. Additional nutrients would make the tree want to put on growth despite being stressed. Here are two links with good general facts on potential causes and what to do. 

acepala.pdf (ufl.edu)

The Cause of Brown Leaves on Japanese Maple Trees (thespruce.com)

For the one year old red maple, the best time to prune is when it is dormant (March-June) although for small branches you can do anytime.

Here is a link to OSU Ohioline discussing when and how to do it properly.

Pruning and Care of Tree Wounds | Ohioline (osu.edu)

You have two very nice trees and I wish you the best of luck for many years of enjoyment of them.