diff --git a/internal-dev/chebi-ext.owl b/internal-dev/chebi-ext.owl
index a08fe415..fb664b23 100644
--- a/internal-dev/chebi-ext.owl
+++ b/internal-dev/chebi-ext.owl
@@ -1091,4 +1091,15 @@
         <rdfs:label xml:lang="en">rutile nanoparticle</rdfs:label>
     </owl:Class>
 
+    <!-- http://purl.enanomapper.net/onto/ENM_9116388 -->
+
+    <owl:Class rdf:about="http://purl.enanomapper.net/onto/ENM_9116388">
+        <rdfs:subClassOf rdf:resource="http://purl.obolibrary.org/obo/CHEBI_60004"/>
+        <rdfs:subClassOf rdf:resource="http://purl.enanomapper.org/onto/ENM_9000248"/>	
+        <rdfs:subClassOf rdf:resource="http://purl.enanomapper.org/onto/ENM_9000006"/>	
+        <rdfs:isDefinedBy xml:lang="en">Cerium(IV)/Cobalt(II,III) mixture of oxide nanoparticles</rdfs:isDefinedBy>
+        <rdfs:label xml:lang="en">CeO2/Co3O4 nanoparticle</rdfs:label>
+    </owl:Class>
+
+
 </rdf:RDF>