You Do Need power plug adapter while traveling from Puerto Rico to Sierra Leone.

Here is Why You Need An Adapter

The outlet and plug type used in Sierra Leone are D and G and in Puerto Rico are A and B. This is how they look like.

Puerto Rico

In Puerto Rico, outlets of type A and B are in use.

Type A

Type B

Sierra Leone

In Sierra Leone, outlets of type D and G are in use.

Type D

Type G