Table 1. Effect of pH on the existing forms of SMX and catalyst surface.

pH	≤3.0	3–6.02	= 6.02	6.02–6.5	>6.5
SMX form	SMX+	SMX	SMX	SMX	SMX−
RAG 3 form	RAG 3+	RAG 3+	RAG 3	RAG 3−	RAG 3−
Effect	Repulsion	No effect	No effect	No effect	Repulsion