MAC of Switch and Router

Switch has a base MAC address and different MAC for every interface

MAC addresses should be unique on each network. They can be same in different networks. i.e MAC-address /layer 2 information changes with each hop.
1]
"Every interface of router have same MAC"
This is right behaviour as each interface of the router will be connected to different network. So it will be highly unlikely that mac-addresss clash would take place.

2]
In case of switch "It shows different MAC for every port"
This is also correct as switches can be used as Layer 3 and as well as in a layer 2 environment. Chances are mac-addresses might clash within same network. Consider cases like SVI/VLAN interfaces, routed interfcaes or plain layer interfaces. So it required unique mac on each interface.

MAC of Switch and Router 

A bridge sends a BPDU frame using the unique MAC address of the port itself as a source address, and a destination address of the STP multicast address 01:80:C2:00:00:00.

There are three types of BPDUs:

• Configuration BPDU (CBPDU), used for Spanning Tree computation
• Topology Change Notification (TCN) BPDU, used to announce changes in the network topology
• Topology Change Notification Acknowledgment (TCA)

BPDUs are exchanged regularly (every 2 seconds by default) and enable switches to keep track of network changes and to start and stop forwarding at ports as required.

Spanning_Tree_Protocol 

How does BPDU transmitted between Switches?