Interoperability between heterogeneous graph data models remains a significant challenge in knowledge graph construction. While both Property Graphs (PG) and RDF models are widely used for data representation, their structural and semantic differences hinder seamless integration and data exchange. In this work, we present PG2RDF, a fully automated and schema-aware pipeline for transforming PG data into RDF. Our method relies on an XML Schema Definition (XSD) to formalize the PG structure and can generate both X3ML or RML mapping rules for deterministic RDF production. By integrating schema discovery, XML annotation, and RDF materialization through the X3ML Engine and RML Mapper, we demonstrate the feasibility of our approach across heterogeneous datasets and their integration into an interoperable Knowledge Graph. PG2RDF ensures URI consistency and accurately represents the PG information.