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

Here is Why You Need An Adapter

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

Sierra Leone

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

Type D

Type G

Puerto Rico

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

Type A

Type B