Structural capital is the knowledge that remains in the organization when the people go home. It commonly consists of descriptions of processes, roles, policies, etc. Basically, it's the know-how of the organization, written down.
Any team expected to fulfill a purpose, requires know-how on how to effectively, efficiently and predictably deliver on that purpose.
That know-how can exist in the head of individuals (human capital), but writing it down (thereby turning it into structural capital) makes it more easily available, alignable and improvable by everyone.
As CEO, it is your responsibility to follow up on and ensure that team leaders identify, develop and expose the structural capital the team needs to succeed.